Novel compound of 4&#39;-thionucleoside, as well as preparation method therefor, pharmaceutical composition thereof and application thereof

ABSTRACT

The present application relates to a method for the prevention or treatment of an abnormal cell proliferative disease in a mammal, wherein the method comprises administering to the mammal an effective amount of a 4′-thionucleoside compound or a pharmaceutically acceptable salt, ester, hydrate, solvate thereof, or racemate thereof, or a mixture thereof.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. application Ser. No.15/558,620, filed 15 Sep. 2017, which is a national stage filing under35 U.S.C. § 371 of PCT/CN2016/077519, filed on 28 Mar. 2016, and claimspriority to Chinese patent application 201510157772.0, filed 3 Apr.2015. Each application is incorporated by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to a novel 4′-thionucleoside compound, toa preparation method thereof, to a pharmaceutical composition comprisingthe compound, and to use thereof. Specifically, the present inventionrelates to a phosphamide derivative of a 4′-thionucleoside, to apreparation method thereof, to a pharmaceutical composition comprisingthe derivative, and to use thereof for the prevention or treatment of anabnormal cell proliferative disease (e.g., tumor, cancer and relateddisorders) or a viral infectious disease.

BACKGROUND OF THE INVENTION

A natural nucleoside is a glycoside comprising a ribose or a deoxyriboseand a base (such as adenine, thymine, guanine, cytosine or uracil), andis an important component of DNA and RNA. Artificially synthesizednucleoside analogues are an important class of chemotherapeutic drugsfor tumor, and are referred to as antimetabolites. The effect thereof ismainly achieved by affecting enzymatic system in tumor cells, therebyinhibiting the synthesis of DNA and RNA. According to statistics fromWHO, cancer is one of the leading causes of death worldwide. Moreover,drug resistance in cancer cells is ubiquitous, and it is urgently neededto develop new anti-cancer drugs for human health. As such, it is anarduous task in the pharmaceutical industry to develop safe and reliableanti-cancer drugs from various perspectives. Treatment employing anorgan specific nucleoside prodrug represents one of the most promisingtherapeutic methods.

Nucleoside drugs, such as gemcitabine, azacitidine, decitabine,cytarabine, fludarabine, cladribine, 6-azauridine, tiazofurine andatromide, etc., have been widely used for the treatment of variouscancers. There are many nucleoside drugs that are currently at differentstages of clinical development.

Gemcitabine is a pyrimidine nucleoside analogue developed by Eli Lillyand Company in the US, and is an important nucleoside-based anticancerdrug as a first-line therapeutic agent for advanced pancreatic cancer,advanced non-small cell lung cancer, localized or metastatic bladdercancer and metastatic breast cancer. It has a broad spectrum ofanti-tumor activity, and is effective for a variety of additional solidtumors. Gemcitabine generally needs to be administered in combinationwith paclitaxel, cisplatin, and/or carboplatin. Gemcitabine has poorcell permeability, low bioavailability, and a short half-life in cells(between 32˜94 min), and thus must be continuously intravenouslyadministered at a high dose (with a recommended dose of 1000 mg/m²), soas to maintain its effective blood drug concentration and toxicity tocancer cells. The dose-limiting toxicity induced by the high dose ofgemcitabine employed affects clinical efficacy, and results in a seriesof side effects and safety issues, such as leukopenia, transaminaseabnormalities, proteinuria, as well as nausea and vomiting, etc. Inaddition, gemcitabine has a number of shortcomings, including lack oftissue specificity which leads to high systemic toxic effects; rapidmetabolism and a short plasma half-life; drug resistance in tumors; pooreffects achieved through oral administration, common requirement ofadministration through intravenous injection, a high dosage and severeside effects; poor efficacy achieved when the drug is administeredalone, and necessity of co-administration with another anti-cancer drug;etc.

Gemcitabine has poor oral bioavailability, and thus generally needs tobe administrated via intravenous injection. The poor oralbioavailability is a result of first-pass metabolism (see Shipley L A.,et al., “Metabolism and disposition of gemcitabine, and oncolyticdeoxycytidine analog, in mice, rats, and dogs”. Drug Metabolism &Disposition. 20(6):849-55, 1992). In addition, when dosed orally,gemcitabine is implicated in causing adverse dose-limiting intestinallesions characterized by moderate-to-marked loss of mucosal epithelium(atrophic enteropathy) throughout the entire length of the intestinaltract in mice given a single oral (gavage) gemcitabine dose of 167, 333,or 500 mg/kg (see Horton N D et al., “Toxicity of single-dose oralgemcitabine in mice”, American Association for Cancer Research, PosterPresentation, Orlando, Fla., Mar. 27-31, 2004). In a previous studyperformed on mice, no death or gastrointestinal toxicity was observedwhen a significant dose was administered intravenously.

Moreover, gemcitabine, like other nucleoside drugs, is a hydrophiliccompound, and thus cannot go through cellular membranes into cells viapassive diffusion, but needs a specific transport protein to bedelivered into tumor cells. Alteration in the nucleoside transportactivity has been considered as an important cause of resistance togemcitabine. Human equilibrative nucleoside transporter 1 (hENT1) is animportant transport protein currently identified for the transportationof gemcitabine into tumor cells. As reduction of intracellular drugaccumulation would likely result in decreased sensitivity togemcitabine, scientists at Clavis Pharma, Norway, have synthesized a5′-elaidic acid ester derivative of gemcitabine, CP-4126, which hassignificantly improved lipophilicity than that of gemcitabine. Studiesshow that CP-4126 can get into tumor cells independent of hENT1transporter, and thus is expected to exhibit a better anti-tumor effectin tumor patients with a low expression of hENT1.

4′-thionucleoside refers to a nucleoside analogue with the oxygen atomin the furanose ring replaced by a sulfur atom. The synthetic route for4′-thionucleosides is long and difficult, which greatly limits the studyof such compounds. U.S. Pat. No. 6,147,058 discloses a 4′-thionucleosidecompound which exhibit inhibitory activity in a colon cancer model innude mice. This compound is shown to have a better effect in inhibitingtumor growth than that of gemcitabine (Cancer Let. 1999, 144, 177-182;Int. J. Cancer, 2005, 114, 1002-1009). U.S. Pat. No. 5,128,458 disclosesa 2′,3′-dideoxy-4′-thioribonucleotides with good effects in thetreatment of both a viral infectious disease (such as HIV, hepatitis Bor C) and an abnormal cell proliferative disease.

Although the 4′-thionucleoside compound has a better effect ininhibiting tumor growth, it also possesses similar shortcomings to thoseof gemcitabine, such as low oral bioavailability, fast metabolism,multiple adverse effects and drug resistance, etc.

Resistance to 4′-thionucleoside drugs is a main reason for the shortsurvival period of a patient. The major causes for the development ofresistance include: 1) lack of corresponding transporter proteins on thesurface of tumor cells, which prevents nucleoside drugs from efficientlypassing through cellular membranes; 2) low efficiency of the conversionfrom the drug to the active species as a triphosphate; and 3) metabolismfrom the drug to an inactive species in the presence of an enzyme.

Since 4′-thionucleoside drug can be quickly metabolized to an inactivespecies and lose activity, no 4′-thionucleoside drug is available forthe treatment of cancers such as liver cancer to date.

So far, problems encountered in the development of 4′-thionucleosidedrugs make them difficult to be approved by authorities. A prodrugapproach has been employed to overcome such problems. Now a lot ofpharmaceutical companies are still working in developing methods fortreating cancers by using other prodrugs (see G. Xu, H. L. McLeod, Clin.Cancer Res., 2001, 7, 3314-3324; M. Rooseboom, J. N. M. Commandeur, N.P. E. Vermeulen, Pharmacol. Rev., 2004, 56, 53-102; W. D. Wu, J.Sigmond, G. J. Peters, R. F. Borch, J. Med. Chem. 2007, 50, 3743-3746).

Upon entry into a body, a nucleoside drug would firstly bephosphorylated to form an active metabolite, monophosphate, through thecatalysis of a corresponding kinase, and the monophosphate is thenconverted to a triphosphate. Monophosphorylation of a nucleoside drug isoften a rate-limiting step in the metabolism of the drug. Kinasescatalyzing the monophosphorylation of a nucleoside in human bodies(thymidine kinase (TK), deoxycytidine kinase (dCK), deoxyguanosinekinase (dGK) and adenosine kinase (AK)) have a limited affinity tonucleosides, and the kinase activity is liable to be inhibited bynucleotide monophosphate (NA-MP). These both limit the in vivoactivation of nucleoside drugs, and affect the exhibition of drugactivity. To address this issue, researchers have attempted to modifynucleoside drugs through phosphorylation, so as to obtain correspondingphosphates or phosphamide (ChemMedChem, 2009, 4, 1779-1791).

However, in development of a drug through modification, it is difficultto determine whether the modified drug can successfully release theparent drug after entering the body, since the parent drug is differentfrom case to case, and the modified drug often has reduced or noefficacy, or result in new side effects. As such, in years of research,4′-thionucleoside compounds currently available still have druggabilityissues, which are difficult to overcome. Today, after gemcitabine is onthe market for many years, there is still no 4′-thionucleoside compoundapproved for clinical application.

SUMMARY OF THE INVENTION

According to an aspect of the present invention, a4′-thio-2′-fluoronucleoside phosphamide compound as represent by Formula(I) is provided,

wherein:

X is hydrogen, C₁₋₆ alkyl, halogen, N₃, OH, CN or SH;

Y is oxygen or sulfur;

R₁, R₂, R₆, and R₇ are each independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl, optionallysubstituted cycloalkyl, optionally substituted aryl, optionallysubstituted heterocyclyl, and optionally substituted heteroaryl, whereinR₂ and R₆ can be connected to form a 3-8 membered carbocyclic ring whichmay contain 0-3 heteroatoms selected from N, O, and S, and may be asaturated, unsaturated, or aromatic ring;

R₃ is selected from the group consisting of optionally substituted aryland optionally substituted heteroaryl;

R₄ is selected from the group consisting of hydrogen, and optionallysubstituted C₁₋₁₀ acyl;

Q is a pyrimidine base or a purine base having the following structure:

R₅ at each occurrence is independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl andoptionally substituted cycloalkyl; and

Z is hydrogen, optionally substituted C₁₋₁₀ alkyl or halogen;

the above expression “optionally substituted” means unsubstituted orsubstituted with one or more substituents independently selected fromthe group consisting of halogen, alkyl, amino, alkylamino, alkoxy,haloalkyl, haloalkoxy, hydroxy, hydroxyalkyl, alkoxyalkyl, amido,sulfonamido, cyano, nitro, nitroso, azido, aldehyde, alkenyl, alkynyl,cycloalkyl, aryl, aralkyl, aryloxy, heteroaryl, heteroaryloxy, acyl,carboxyl, alkylcarbonyl, arylcarbonyl, heteroarylcarbonyl, andcarboxylate; and the substituents can be connected to each other to forma 3-8 membered saturated, unsaturated or aromatic ring containing 0-3heteroatoms selected from N, O, and S;

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

According to another aspect of the present invention, a pharmaceuticalcomposition or a pharmaceutical formulation is provided, wherein thepharmaceutical composition or the pharmaceutical formulation comprisesthe above 4′-thio-2′-fluoronucleoside phosphamide compound as representby Formula (I), or a pharmaceutically acceptable salt, ester, hydrate,solvate, isomer thereof, any crystalline form or racemate thereof, ametabolite thereof, or a mixture thereof, as an active ingredient, and apharmaceutically acceptable carrier, adjuvant, excipient or equivalentpharmaceutically acceptable medium. The pharmaceutical composition orthe pharmaceutical formulation can be in a form suitable foradministration to a mammal, including a solid preparation, a semi-solidpreparation, a liquid preparation, and a gas preparation, etc.

According to a further aspect of the present invention, a use of theabove 4′-thio-2′-fluoronucleoside phosphamide compound as represent byFormula (I) in the manufacture of a medicament for the prevention ortreatment of an abnormal cell proliferative disease or a viralinfectious disease in a mammal is provided. The abnormal cellproliferative disease in a mammal is e.g. cancer and/or tumor andrelated disorders thereof. Optionally, the medicament further comprisesan additional anti-tumour agent.

According to a further aspect of the present invention, a method for theprevention or treatment of an abnormal cell proliferative disease and/ora viral infectious disease in a mammal is provided, wherein the methodcomprises administering to the mammal an effective amount of the above4′-thio-2′-fluoronucleoside phosphamide compound as represent by Formula(I), or a pharmaceutically acceptable salt, ester, hydrate, solvate,isomer thereof, any crystalline form or racemate thereof, a metabolitethereof, or a mixture thereof. The abnormal cell proliferative diseasein a mammal is e.g. cancer and/or tumor and related disorders thereof ina mammal.

According to a further aspect of the present invention, the above4′-thio-2′-fluoronucleoside phosphamide compound as represent by Formula(I), or a pharmaceutically acceptable salt, ester, hydrate, solvate,isomer thereof, any crystalline form or racemate thereof, a metabolitethereof, or a mixture thereof for the prevention or treatment of anabnormal cell proliferative disease and/or a viral infectious disease ina mammal is provided. The abnormal cell proliferative disease in amammal is e.g. cancer and/or tumor and related disorders thereof in amammal.

According to a further aspect of the present invention, a method forpreparing the above compound as represent by Formula (I) is provided,wherein the method comprises the following steps:

wherein each of the groups is as defined above, and step 1 is preferablyperformed in the presence of POCl₃.

BRIEF DESCRIPTION OF THE DRAWING

The present invention will now be described in more detail withreference to the accompanying drawing, wherein:

FIG. 1 shows the effects of the compound of Example 8 (C8) on fourdifferent tumor cells at various concentrations.

DETAILED DESCRIPTION OF THE INVENTION

Compound

An embodiment of the present invention provides a compound of Formula(I),

wherein:

X is hydrogen, C₁₋₆ alkyl, halogen, N₃, OH, CN or SH;

Y is oxygen or sulfur;

R₁, R₂, R₆, and R₇ are each independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl, optionallysubstituted cycloalkyl, optionally substituted aryl, optionallysubstituted heterocyclyl, and optionally substituted heteroaryl, whereinR₂ and R₆ can be connected to form a 3-8 membered carbocyclic ring whichmay contain 0-3 heteroatoms selected from N, O, and S, and may be asaturated, unsaturated, or aromatic ring;

R₃ is selected from the group consisting of optionally substituted aryland optionally substituted heteroaryl;

R₄ is selected from the group consisting of hydrogen, and optionallysubstituted C₁₋₁₀ acyl;

Q is a pyrimidine base or a purine base having the following structure:

R₅ at each occurrence is independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl andoptionally substituted cycloalkyl; and

Z is hydrogen, optionally substituted C₁₋₁₀ alkyl or halogen;

the above expression “optionally substituted” means unsubstituted orsubstituted with one or more substituents selected from the groupconsisting of halogen, alkyl, amino, alkylamino, alkoxy, haloalkyl,haloalkoxy, hydroxy, hydroxyalkyl, alkoxyalkyl, amido, sulfonamido,cyano, nitro, nitroso, azido, aldehyde, alkenyl, alkynyl, cycloalkyl,aryl, aralkyl, aryloxy, heteroaryl, heteroaryloxy, acyl, carboxyl,alkylcarbonyl, arylcarbonyl, heteroarylcarbonyl, and carboxylate; andthe substituents can be connected to each other to form a 3-8 memberedsaturated, unsaturated or aromatic ring containing 0-3 heteroatomsselected from N, O, and S;

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

Another embodiment of the present invention provides the above compoundof Formula (I), wherein:

Q is a pyrimidine base having the following structure:

and

Z is hydrogen, methyl, or halogen;

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein

Q is a pyrimidine base having a structure as shown below:

and

Z is hydrogen, methyl, or halogen;

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein:

R₁, R₂, R₆, and R₇ are each independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl, optionallysubstituted cycloalkyl, and optionally substituted aryl, wherein R₂ andR₆ can be connected to form a 3-8 membered carbocyclic ring which maycontain 0-3 heteroatoms selected from N, O, and S, and may be asaturated, unsaturated, or aromatic ring;

Q is cytosine having the following structural formula:

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein Q is selected from

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein X is hydrogen or halogen, and thehalogen is fluorine, chlorine, bromine or iodine.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein Y is oxygen.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein R₁, R₂, R₆, and R₇ are eachindependently selected from the group consisting of hydrogen, optionallysubstituted C₁₋₁₀ alkyl, and optionally substituted aryl (preferablyoptionally substituted C₆₋₁₄ aryl), the above expression “optionallysubstituted” means unsubstituted or substituted with one or moresubstituents selected from the group consisting of halogen, C₁₋₆ alkyl,and C₆₋₁₄ aryl. Most preferably, R₁, R₂, R₆, and R₇ are eachindependently selected from the group consisting of hydrogen, methyl,ethyl, propyl, isopropyl, phenyl, benzyl, and 4-fluorobenzyl.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein R₃ is selected from the groupconsisting of optionally substituted aryl, preferably optionallysubstituted C₆₋₁₄ aryl, more preferably optionally substituted phenyl,the above expression “optionally substituted” means unsubstituted orsubstituted with one or more substituents selected from the groupconsisting of halogen, C₁₋₆ alkyl, and C₁₋₆ alkoxy, and the substituentscan be connected to each other to form a 3-8 membered saturated,unsaturated or aromatic ring containing 0-3 (e.g. 1, 2, or 3) O. Mostpreferably, R₃ has a structure as shown below:

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein R₄ is hydrogen.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein R₅ at each occurrence is independentlyselected from the group consisting of hydrogen and optionallysubstituted C₁₋₁₀ alkyl (e.g. hept-4-yl).

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein Z is hydrogen, methyl, fluorine orchlorine.

The present invention encompasses the above compound of Formula (I)obtained by any combination of groups in the definitions of theabove-described various embodiments, and would not be constrained byeach individual embodiment.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein Q is

X is hydrogen, C₁₋₆ alkyl, halogen, N₃, OH, CN or SH;

Y is oxygen or sulfur;

R₁, R₂, R₆, and R₇ are each independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl, optionallysubstituted cycloalkyl, optionally substituted aryl, optionallysubstituted heterocyclyl, and optionally substituted heteroaryl, whereinR₂ and R₆ can be connected to form a 3-8 membered carbocyclic ring whichmay contain 0-3 heteroatoms selected from N, O, and S, and may be asaturated, unsaturated, or aromatic ring;

R₃ is selected from the group consisting of optionally substituted aryland optionally substituted heteroaryl;

R₄ is selected from the group consisting of hydrogen, and optionallysubstituted C₁₋₁₀ acyl;

R₅ at each occurrence is independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl andoptionally substituted cycloalkyl; and

Z is hydrogen, methyl or halogen;

the above expression “optionally substituted” means unsubstituted orsubstituted with one or more substituents selected from the groupconsisting of halogen, alkyl, amino, alkylamino, alkoxy, haloalkyl,haloalkoxy, hydroxy, hydroxyalkyl, alkoxyalkyl, amido, sulfonamido,cyano, nitro, nitroso, azido, aldehyde, alkenyl, alkynyl, cycloalkyl,aryl, aralkyl, aryloxy, heteroaryl, heteroaryloxy, acyl, carboxyl,alkylcarbonyl, arylcarbonyl, heteroarylcarbonyl, and carboxylate; andthe substituents can be independent from each other, or be connected toeach other to form a 3-8 membered saturated, unsaturated or aromaticring containing 0-3 heteroatoms selected from N, O, and S;

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

A further embodiment of the present invention provides the abovecompound of Formula (I), wherein Q is cytosine having the followingstructural formula:

X is hydrogen, C₁₋₆ alkyl, halogen, N₃, OH, CN or SH;

Y is oxygen or sulfur;

R₁, R₂, R₆, and R₇ are each independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl, optionallysubstituted cycloalkyl, and optionally substituted aryl, wherein R₂ andR₆ can be connected to form a 3-8 membered carbocyclic ring which maycontain 0-3 heteroatoms selected from N, O, and S, and may be asaturated, unsaturated, or aromatic ring;

R₃ is selected from the group consisting of optionally substituted aryland optionally substituted heteroaryl;

R₄ is selected from the group consisting of hydrogen, and optionallysubstituted C₁₋₁₀ acyl;

R₅ at each occurrence is independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl andoptionally substituted cycloalkyl; and

Z is hydrogen, optionally substituted C₁₋₁₀ alkyl or halogen;

the above expression “optionally substituted” means unsubstituted orsubstituted with one or more substituents selected from the groupconsisting of halogen, alkyl, amino, alkylamino, alkoxy, haloalkyl,haloalkoxy, hydroxy, hydroxyalkyl, alkoxyalkyl, amido, sulfonamido,cyano, nitro, nitroso, azido, aldehyde, alkenyl, alkynyl, cycloalkyl,aryl, aralkyl, aryloxy, heteroaryl, heteroaryloxy, acyl, carboxyl,alkylcarbonyl, arylcarbonyl, heteroarylcarbonyl, and carboxylate; andthe substituents can be connected to each other to form a 3-8 memberedsaturated, unsaturated or aromatic ring containing 0-3 heteroatomsselected from N, O, and S;

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

A further embodiment of the present invention provides the abovecompound of Formula (I),

wherein:

X is hydrogen, C₁₋₆ alkyl, halogen, N₃, OH, CN or SH;

Y is oxygen or sulfur;

R₁, R₂, R₆, and R₇ are each independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl, optionallysubstituted cycloalkyl, and optionally substituted aryl, wherein R₂ andR₆ can be connected to form a 3-8 membered carbocyclic ring which maycontain 0-3 heteroatoms selected from N, O, and S, and may be asaturated, unsaturated, or aromatic ring;

R₃ is selected from the group consisting of optionally substituted aryland optionally substituted heteroaryl;

R₄ is selected from the group consisting of hydrogen, and optionallysubstituted C₁₋₁₀ acyl;

Q is a purine base having the following structure:

R₅ at each occurrence is independently selected from the groupconsisting of hydrogen, optionally substituted C₁₋₁₀ alkyl andoptionally substituted cycloalkyl; and

Z is hydrogen, methyl or halogen;

the above expression “optionally substituted” means unsubstituted orsubstituted with one or more substituents selected from the groupconsisting of halogen, alkyl, amino, alkylamino, alkoxy, haloalkyl,haloalkoxy, hydroxy, hydroxyalkyl, alkoxyalkyl, amido, sulfonamido,cyano, nitro, nitroso, azido, aldehyde, alkynyl, alkenyl, cycloalkyl,aryl, aralkyl, aryloxy, heteroaryl, heteroaryloxy, acyl, carboxyl,alkylcarbonyl, arylcarbonyl, heteroarylcarbonyl, and carboxylate; andthe substituents can be independent from each other, or be connected toeach other to form a 3-8 membered saturated, unsaturated or aromaticring containing 0-3 heteroatoms selected from N, O, and S;

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

A further embodiment of the present invention provides the abovecompound of Formula (I), which is a 4′-thio-2,2-difluoronucleosidephosphamide compound (i.e., X in Formula (I) is F), and Q is apyrimidine group in its definition, and the remaining substituents areeach as defined as above.

A further embodiment of the present invention provides the abovecompound of Formula (I), which is a 4′-thio-2,2-difluoronucleosidephosphamide compound (i.e., X in Formula (I) is F), and Q is a cytosinegroup in its definition, and the remaining substituents are each asdefined as above.

The preferred compounds of the present invention are as follows:

or a pharmaceutically acceptable salt, ester, solvate, hydrate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof.

In extensive research, structural modifications and activity screeningare made to the 4′-thio-2′-fluoronucleoside compound in the presentapplication, and the compound with a specific phosphamide substituent atposition 5 of the present invention is obtained. The compound of thepresent invention has superior pharmaceutical efficacy, including ananti-tumor/anti-cancer effect and an effect on a viral infectiousdisease, as well as increased liposolubility, improved bioavailability,reduced irritation, and improved absorption. Issues in metabolic ratepresent in existing drugs are addressed, toxicity is significantlyreduced, and safety profile is improved. The pharmacological effect canbe achieved through various administration routes.

The compound of Formula (I) described in the present invention refers toall the compounds covered by Formula (I), pharmaceutically acceptablesalts, esters, hydrates, solvates, isomers thereof, or any crystallineform or racemate thereof, or metabolites thereof, or mixtures thereof.

A further embodiment of the present invention provides a pharmaceuticalcomposition, comprising the compound of Formula (I), or apharmaceutically acceptable salt, ester, hydrate, solvate, isomerthereof, or any crystalline form or racemate thereof, or a metabolitethereof, or a mixture thereof, as an active ingredient, and apharmaceutically acceptable carrier, adjuvant, excipient or equivalentpharmaceutically acceptable medium.

The pharmaceutical composition may comprise the compound of Formula (I)in a unit dose ranging from 0.1-1000 mg, preferably 1-800 mg, morepreferably 10-600 mg, particularly preferably 50-450 mg, and mostpreferably 100-300 mg.

The pharmaceutical composition may be in a form of e.g., a solid,semi-solid, liquid, or gas preparation. In particular, the solidpreparation is e.g. a tablet, capsule, powder, granule, or suppository,etc.; the liquid preparation is e.g. a solution, suspension orinjection. The composition can also be a preparation such as liposome,and microsphere. Particularly, the pharmaceutical composition is in adosage form suitable for oral administration.

The pharmaceutical composition can be in a form of a single dose unit ormultiple dose units, each of the dose unit comprises a suitable amountof the compound of Formula (I), or a pharmaceutically acceptable salt,ester, hydrate, solvate, isomer thereof, or any crystalline form orracemate thereof, or a metabolite thereof, or a mixture thereof.

A further embodiment of the present invention provides a use of thecompound of Formula (I), or a pharmaceutically acceptable salt, ester,hydrate, solvate, isomer thereof, any crystalline form or racematethereof, a metabolite thereof, or a mixture thereof as an activeingredient in the manufacture of a medicament for the prevention ortreatment of an abnormal cell proliferative disease or a viralinfectious disease in a mammal. The medicament may comprise the compoundof Formula (I) in a unit dose ranging from 0.1-1000 mg, preferably 1-800mg, more preferably 10-600 mg, particularly preferably 50-450 mg, andmost preferably 100-300 mg.

A further embodiment of the present invention provides a method for thetreatment or prevention of an abnormal cell proliferative disease or aviral infectious disease in a mammal, wherein the method comprisesadministering to the mammal an effective amount of the compound ofFormula (I), or a pharmaceutically acceptable salt, ester, hydrate,solvate, isomer thereof, any crystalline form or racemate thereof, ametabolite thereof, or a mixture thereof.

A further embodiment of the present invention provides the compound ofFormula (I), or a pharmaceutically acceptable salt, ester, hydrate,solvate, isomer thereof, any crystalline form or racemate thereof, ametabolite thereof, or a mixture thereof for the treatment or preventionof an abnormal cell proliferative disease or a viral infectious diseasein a mammal.

The abnormal cell proliferative disease or the viral infectious diseaseis e.g. cancer and/or tumor and related disorders thereof. The cancerand/or tumor include(s) tumors and/or cancers and related disorders inesophagus, stomach, intestine, rectum, mouth, pharynx, larynx, lung,colon, breast, uterus, endometrium, ovary, prostate, testis, bladder,kidney, liver, pancreas, bone, connective tissue, skin, eye, brain andcentral nervous system, as well as thyroid cancer, leukemia, Hodgkindisease, lymphoma and myeloma.

The compound of Formula (I), or a pharmaceutically acceptable salt,ester, hydrate, solvate, isomer thereof, any crystalline form orracemate thereof, a metabolite thereof, or a mixture thereof can beadministered in combination with an additional anti-tumour agent for theprevention or treatment of an abnormal cell proliferative disease (suchas cancer and/or tumor and related disorders thereof) in a mammal. Theadditional anti-tumor agent refers to a substance with activity againsttumor/cancer and related disorders thereof, and includes but is notlimited to erlotinib or cisplatin.

The compound of Formula (I), or a pharmaceutically acceptable salt,ester, hydrate, solvate, isomer thereof, any crystalline form orracemate thereof, a metabolite thereof, or a mixture thereof can beadministered in combination with an additional anti-viral agent for theprevention or treatment of a viral infectious disease. The additionalanti-viral agent includes but is not limited to lamivudine, entecavir,nevirapine or stavudine.

The expression “administered in combination” encompasses two or moredrugs are administered simultaneously, sequentially, or alternatively,and particularly encompasses two or more drugs are prepared into one ormore dose units, so as to obtain a pharmaceutical product suitable foradministration in combination, which is administered to a mammal in needthereof.

A further embodiment of the present invention provides a method forpreparing the compound of Formula (I), comprising the following steps:

wherein each of the groups is as defined above, and step 1 is preferablyperformed in the presence of POCl₃.

Unless otherwise defined in the context, all technical and scientificterms used herein are intended to have the same meaning as commonlyunderstood by a person skilled in the art. References to techniquesemployed herein are intended to refer to the techniques as commonlyunderstood in the art, including variations on those techniques orsubstitutions of equivalent techniques which would be apparent to aperson skilled in the art. While it is believed that most of thefollowing terms will be readily understood by a person skilled in theart, the following definitions are nevertheless put forth to betterillustrate the present invention.

The expression “as defined above” refers to the first and/or thebroadest definition provided in the application, as well as scenariossuitable in the context.

The terms “contain”, “include”, “comprise”, “have”, or “relate to”, aswell as other variations used herein are inclusive or open-ended, and donot exclude additional, unrecited elements or method steps.

As used herein, the term “compound of the present invention” generallyrefers to the scope of compounds defined by above Formula (I), orpharmaceutically acceptable salts, esters, hydrates, solvates, isomersthereof, any crystalline form or racemate thereof, metabolites thereof,or mixtures thereof.

As used herein, the term “metabolite” refers to a compound generated invivo after a drug is applied to a subject in need thereof.

As used herein, the term “pharmaceutically acceptable salt” refers tothose salts which retain the biological effectiveness and properties ofthe parent compound, and can be prepared in the following manner: aproton-accepting moiety is partially protonated and/or a proton-donatingmoiety is partially deprotonated. It should be noted that the partialprotonation of the proton-accepting moiety results in a cationicspecies, the charge of which is balanced by the presence of aphysiological anion, while the partial deprotonation of theproton-donating moiety results in an anionic species, the charge ofwhich is balanced by the presence of a physiological cation.

A pharmaceutically acceptable salt of the compound of Formula (I)includes an acid addition salt and a base addition salt thereof.

A suitable acid addition salt is formed from an acid which forms anon-toxic salt and includes an inorganic acid and an organic acid. Inthe present invention, a suitable inorganic acid is an acid as definedin the field of chemistry, such as hydrochloric acid, sulfuric acid orphosphoric acid, etc. A suitable organic acid includes an organicsulfonic acid, an organic carboxylic acid, or an amino acid, etc. Asuitable organic sulfonic acid is e.g. C₆₋₁₆ aryl sulfonic acid, C₆₋₁₆heteroaryl sulfonic acid, or C₁₋₁₆ alkyl sulfonic acid, and a suitableorganic carboxylic acid is e.g. monocarboxylic acid or polycarboxylicacid, including C₁₋₁₆ alkyl carboxylic acid, C₆₋₁₆ aryl carboxylic acidand C₄₋₁₆ heteroaryl carboxylic acid. The organic carboxylic acid canalso be e.g. an amino acid, various kinds of which are suitable,particularly natural amino acids which are found as components ofproteins. Specific examples of salts formed from the above acids includethe acetate, adipate, aspartate, benzoate, besylate,bicarbonate/carbonate, bisulfate/sulfate, borate, camphorsulfonate,citrate, cyclamate, edisylate, esylate, formate, fumarate, gluceptate,gluconate, glucuronate, hexafluorophosphate, hydrochloride/chloride,hydrobromide/bromide, hydroiodide/iodide, isethionate, lactate, malate,maleate, malonate, mesylate, methylsulfate, naphthylate, 2-napsylate,nicotinate, nitrate, orotate, oxalate, palmitate, pamoate,phosphate/hydrogen phosphate/dihydrogen phosphate, pyroglutamate,saccharate, stearate, succinate, tannate, tartrate, tosylate,trifluoroacetate and xinofoate salts.

A suitable base addition salt is formed from a base which formsnon-toxic salts and includes an inorganic base and an organic base.Specific examples include the aluminum, arginine, benzathine, calcium,choline, diethylamine, diolamine, glycine, lysine, magnesium, meglumine,olamine, potassium, sodium, tromethamine and zinc salts.

For a review on suitable salts, see “Handbook of Pharmaceutical Salts:Properties, Selection, and Use” by Stahl and Wermuth (Wiley-VCH, 2002).Methods for preparing pharmaceutically acceptable salts of compounds ofthe present invention are known to a person skilled in the art.

As used herein, the term “isomer” refers to a different compound with asame molecular formula, and includes a stereoisomer. The term“stereoisomer” is an isomer that merely differs in the arrangement ofatoms in space. α- and β-indicate the specific stereochemicalconfiguration of a substituent at an asymmetric carbon atom in achemical structure as drawn.

The compound of the present invention may have one or more chiralcenters, and may, therefore, exist in a variety of stereoisomericconfigurations. Due to the presence of these chiral centers, thecompound of the present invention can exist as a racemate, a mixture ofenantiomers, as well as mixtures of each enantiomer and a diastereomerand of diastereomers. All such racemates, enantiomers, and diastereomersare within the scope of “the compound of the present invention”. Theterms “R” and “S” are used in organic chemistry to denote specificconfigurations of a chiral center.

The compound of the present invention can exist as a hydrate, or as asolvate, wherein the compound of the present invention contains a polarsolvent, in particular water, methanol or ethanol for example as astructural element of the crystal lattice of the compound. The amount ofthe polar solvent, in particular water, may exist in a stoichiometric ornon-stoichiometric ratio.

The present invention includes all possible crystalline forms, orpolymorphs, of the compound of the present invention, either as a singlepolymorph, or as a mixture of more than one polymorphs, in any ratio.

The term “optional” or “optionally” means an element may be, but is notnecessarily, present in a corresponding situation or condition. The termcomprises an example wherein a substituent is or is not present, andalso comprises an example which is substituted with one or moresubstituents. The term “substituted” means that one or more (e.g., one,two, three, or four) hydrogens on the designated atom is replaced with aselection from the indicated group, provided that the designated atom'snormal valency under the existing circumstances is not exceeded, andthat the substitution results in a stable compound. Combinations ofsubstituents and/or variables are permissible only if such combinationsresult in stable compounds. In the compound of Formula (I) of thepresent invention, the expression “optionally substituted” coverssituations where a compound is substituted with one or moresubstituents, and when the expression “optionally substituted” refers toa situation where a compound is substituted with multiple substituents,the substituents may be appropriately connected to each other to form asaturated, unsaturated or aromatic ring containing 0-3 heteroatomsselected from oxygen (O), nitrogen (N), and sulfur (S), and suchsaturated, unsaturated or aromatic ring may further form a ring with thegroup being substituted. For example, specific examples of the term“optionally substituted aryl” include dihydrobenzothiophenyl, as well asa group having the follow structure:

As used herein, the term “alkyl” refers to an unbranched or branched,chain or cyclic, saturated, monovalent hydrocarbon residue, whichpreferably contains 1 to 14 carbon atoms (C₁₋₁₄ alkyl), more preferablycontains 1 to 10 carbon atoms (C₁₋₁₀ alkyl), more preferably contains 1to 6 carbon atoms (C₁₋₆ alkyl), and particularly preferably contains 1to 4 carbon atoms (C₁₋₄ alkyl). Examples of an alkyl group include, butare not limited to, lower alkyl groups including methyl, ethyl, propyl,isopropyl, n-butyl, isobutyl, tert-butyl or pentyl, isopentyl,neopentyl, hexyl, heptyl (e.g., hept-4-yl) and octyl.

As used herein, the term “cycloalkyl” refers to a saturated,non-aromatic, monocyclic or polycyclic (such as bicyclic) hydrocarbonring. When a cycloalkyl comprises two or more rings, the rings can befused together. In its ring, a cycloalkyl group may contain 3 to 10atoms (C₃₋₁₀ cycloalkyl), preferably 3 to 8 ring atoms (C₃₋₈cycloalkyl), more preferably 3 to 6 ring atoms (C₃₋₆ cycloalkyl), andparticularly preferably 3 to 4 ring atoms (C₃₋₄ cycloalkyl). Thecycloalkyl group includes, but is not limited to monocycles such ascyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl, cyclononyl, or bicycicles, including spiro, fused, orbridged systems (such as bicyclo[1.1.1]pentanyl, bicyclo[2.2.1]heptanyl,bicyclo[3.2.1]octanyl or bicyclo[5.2.0]nonanyl, decahydronaphthalenyl,etc.), optionally substituted with 1 or more (such as 1 to 3) suitablesubstituents.

Unless otherwise indicated, the term “alkenyl” as used herein refers toa hydrocarbon residue having 2 to 10 carbon atoms and having one or twoolefinic double bonds, and it preferably contains 2-8 carbon atoms (C₂₋₈alkenyl), more preferably contains 2 to 6 carbon atoms (C₂₋₆ alkenyl),and particularly preferably contains 2 to 4 carbon atoms (C₂₋₄ alkenyl).Examples of an alkenyl group include vinyl, 1-propenyl, 2-propenyl or2-butenyl, etc.

Unless otherwise indicated, the term “alkynyl” as used herein refers toan unbranched or branched hydrocarbon chain group having 2 to 10 carbonatoms (C₂₋₁₀ alkynyl), and having one or two triple bonds, and itpreferably contains 2-8 carbon atoms (C₂₋₈ alkynyl), more preferablycontains 2 to 6 carbon atoms (C₂₋₆ alkynyl), and particularly preferablycontains 2 to 4 carbon atoms (C₂₋₄ alkynyl). Examples of an alkynylgroup are ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl or3-butynyl.

As used herein, the term “amino” represents —NH₂, and alkylaminorepresents —NR′R″, wherein R and R″ are the same or different, and are Hor an alkyl or cycloalkyl group as defined above.

As used herein, the term “alkoxy” represents —O-alkyl, wherein alkyl isas defined above (e.g., C₁₋₁₄ alkyl, C₁₋₁₀ alkyl, C₁₋₆ alkyl, or C₁₋₄alkyl), such as methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy,isobutoxy, tert-butoxy, pentoxy, hexoxy, etc., as well as isomersthereof.

As used herein, the term “halogen” or “halo” refers to fluorine,chlorine, bromine or iodine.

As used herein, the term “haloalkyl” refers to the alkyl group asdefined above, wherein 1, 2, 3, or more hydrogen atoms are replaced withhalogens. Examples are 1-fluoromethyl, 1-chloromethyl, 1-bromomethyl,1-iodomethyl, trifluoromethyl, trichloromethyl, tribromomethyl,triiodomethyl, 1-fluoroethyl, 1-chloroethyl, 1-bromoethyl, 1-iodoethyl,2-fluoroethyl, 2-chloroethyl, 2-bromoethyl, 2-iodoethyl,2,2-dichloroethyl, 3-bromopropyl or 2,2,2-trifluoroethyl.

As used herein, the term “haloalkoxy” refers to the alkoxy group asdefined above, wherein 1, 2, 3, or more hydrogen atoms are replaced withhalogens.

As used herein, the term “acyl” represents a group of formula —C(═O)R,wherein R is hydrogen or an alkyl group as defined above (e.g., C₁₋₁₄alkyl, C₁₋₁₀ alkyl, C₁₋₆ alkyl, or C₁₋₄ alkyl).

As used herein, the term “alkylcarbonyl” represents a group of formula—C(═O)R, wherein R is an alkyl group as defined above (e.g., C₁₋₁₄alkyl, C₁₋₁₀ alkyl, C₁₋₆ alkyl, or C₁₋₄ alkyl).

As used herein, the term “amido” represents a group of formula—NC(═O)R′R″, wherein R and R′ are the same or different, and arehydrogen or an alkyl group as defined above (e.g., C₁₋₁₄ alkyl, C₁₋₁₀alkyl, C₁₋₆ alkyl, or C₁₋₄ alkyl).

As used herein, the term “hydroxyalkyl” represents a group of formula—R—OH, wherein R is an alkylene group. Unless otherwise indicated, theterm “alkylene” as used herein refers to a divalent, saturated, straighthydrocarbon group containing 1 to 10 carbon atoms (C₁₋₁₀ alkylene), morepreferably 1 to 6 carbon atoms (C₁₋₆ alkylene), and particularlypreferably 1 to 4 carbon atoms (C₁₋₄ alkylene), or a branched,saturated, divalent hydrocarbon group containing 3-10 carbon atoms(C₃₋₁₀ alkylene), more preferably 3-8 carbon atoms (C₃₋₈ alkylene), andparticularly preferably 3-5 carbon atoms (C₃₋₅ alkylene). Examples of analkylene group include, but are not limited to, methylene, ethylene,propylene, 2-methyl-propylene, butylene and 2-ethylbutylene, etc.

As used herein, the term “aryl” refers to a group having at least onearomatic ring, i.e., having a conjugated i-electron system, and includesa monocyclic aryl group, and a bicyclic aryl group. It contains 6-14carbon atoms (C₆₋₁₄ aryl), such as phenyl and naphthyl, etc. Optionallysubstituted aryl includes an aryl group substituted with multiplesubstituents, and the substituents can be appropriately connected toeach other to form a saturated, unsaturated or aromatic ring containing0-3 heteroatoms selected from N, O, and S. The aryl group preferablyincludes the following groups:

As used herein, the term “aralkyl” represents group R′R″—, wherein R′ isan aryl group as defined herein, and R″ is an alkylene group as definedherein. It is to be understood that the point of attachment of thearalkyl moiety would be at the alkylene group. Normally, the aryl groupmay contain 6-14 carbon atoms, and the alkyl group may contain 1-6carbon atoms. Exemplary aralkyl includes, but is not limited to benzyl,4-fulorobenzyl, phenylethyl, phenylpropyl, and phenylbutyl.

As used herein, the term “aryloxy” represents —O—R, and R is an arylgroup as defined above.

As used herein, the term “arylcarbonyl” represents a group of formula—C(═O)Ar, wherein Ar is an aryl group as defined above.

As used herein, the term “heterocyclyl” refers to a 3-16 memberedsaturated or unsaturated ring containing 1-4 (e.g., one, two, three, orfour) heteroatoms selected from N, O, S, and P, with the remaining atomsas carbon atoms. In particular, a 3-10 membered heterocyclyl is a grouphaving 3-10 carbon atoms as well as heteroatoms in its rings, such as,but not limited to, oxiranyl, aziridinyl, azetidinyl, oxetanyltetrahydrofuranyl, dioxolinyl, pyrrolidinyl, pyrrolidinonyl,imidazolidinyl, pyrazolidinyl, pyrrolinyl, tetrahydropyranyl,piperidinyl, morpholinyl, dithianyl, thiomorpholinyl, piperazinyl, ortrithianyl.

As used herein, the term “heteroaryl” refers to a cyclic aromatic grouphaving 1 to 3 heteroatoms selected from N, O and S atoms as ring atoms,with the remaining ring atoms as carbon atoms, wherein the ring is a4-16 membered monocycle or fused ring, preferably a 5-12 memberedmonocycle or fused ring, or a 5-8 membered monocycle or fused ring.Examples of a heteroaryl group include, but are not limited to, furyl,thienyl, oxazolyl, isoxazolyl, thiazolyl, isothiazolyl, oxadiazolyl,triazolyl, thiadiazolyl, pyridyl, pyrrolyl, pyrazolyl, N-alkylpyrrolyl,pyrimidinyl, pyrazinyl, imidazolyl, pyridazinyl, phthalazinyl,phthalazin-1-(2H)-1-yl, pyrido[3,2-d]pyridazin-5(6H)-8-yl, triazinyl,etc., as well as benzo derivatives thereof.

As used herein, the term “heteroarylcarbonyl” is defined similar to thedefinition of “arylcarbonyl group”, and represents a group of formula—C(═O)R, wherein R is a heteroaryl group as defined above.

As used herein, the term “heteroaryloxy” represents a group of formulaheteroaryl-O—, wherein the heteroaryl group is as defined above.

As used herein, the term “sulfonamido” represents a group of formula—SO₂NR′R″, wherein R and R′ are the same or different, and are eachindependently hydrogen or an alkyl or cycloalkyl group as defined above.

As used herein, the term “carboxyl” represents a group of formula —COOH,and the term “carboxylate” represents —COOR, wherein R eachindependently represents an alkyl group as defined above.

In the general formula or specific compounds of the present invention, agroup, or an atom, or a radical each includes a group, or an atom, or aradical with substitution of an isotope, for example, “hydrogen”includes H, ²H (deuterium), or ³H (tritium); a C₁₋₁₄ alkyl groupincludes an alkyl group wherein one or more, or all of the carbon atomsare ¹²C, ¹³C, or ¹⁴C; and further exemplary examples include isotopes ofN, P, or O.

As used herein, the term “pharmaceutically acceptable carrier” refers toinactive ingredients in a pharmaceutical composition or a pharmaceuticalpreparation that do not cause significant irritation and do notinterfere with the nature of the biologically active compounds appliedin an organism, and it includes a diluent, adjuvant, excipient orequivalent pharmaceutically acceptable medium administered together witha therapeutic agent.

As used herein, the term “excipient” refers to a substance for thepreparation of a pharmaceutical composition, and it is generally safe,non-toxic, and neither biologically nor otherwise undesirable, andincludes various excipients suitable for veterinary use as well as humanpharmaceutical use.

The pharmaceutically acceptable carrier which can be employed in thepharmaceutical composition of the present invention includes, but is notlimited to sterile liquids, such as water and oils, including those ofpetroleum, animal, vegetable or synthetic origin, such as peanut oil,soybean oil, mineral oil, sesame oil and the like. Water is an exemplarycarrier when the pharmaceutical composition is administeredintravenously. Physiological salines as well as aqueous dextrose andglycerol solutions can also be employed as liquid carriers, particularlyfor injectable solutions. Suitable pharmaceutical excipients includestarch, glucose, lactose, sucrose, gelatin, maltose, chalk, silica gel,sodium stearate, glycerol monostearate, talc, sodium chloride, driedskim milk, glycerol, propylene glycol, water, ethanol and the like. Thecomposition, if desired, can also contain minor amounts of wetting oremulsifying agents, or pH buffering agents. Oral formulations caninclude standard carriers such as pharmaceutical grades of mannitol,lactose, starch, magnesium stearate, sodium saccharine, cellulose,magnesium carbonate, etc. Examples of suitable pharmaceutical carriersare described in e.g. Remington's Pharmaceutical Sciences (1990).

As used herein, the term “formulation” or “dosage form” shall includesolid, semi-solid, liquid, or gas formulations. The formulation ordosage form includes, but is not limited to, tablets, capsules,lozenges, hard candies, powders, sprays, creams, salves, suppositories,gels, pastes, lotions, ointments, aqueous suspensions, injectablesolutions, elixirs, syrups, and the like. Those skilled in the art willappreciate that, depending on the desired dose and pharmacokineticparameters, the compound of the present invention may be prepared asdifferent formulations.

The unit dosage range of the compound of the present invention is0.1-1000 mg, preferred unit dosage range is 1-800 mg, more preferredunit dosage range is 10-600 mg, particularly preferred unit dosage rangeis 50-450 mg, and the most preferred unit dosage range is 100-300 mg.The formulation or dosage form of the present invention may contain asingle or multiple unit dosage of the compound of the present invention.

The compound of the present invention is preferably for oraladministration. In various situations, other administration routes maybe employed or even preferred, such as intravenous, intraarterial,subcutaneous, intraperitoneal, intramuscular, or transdermaladministration, or administration via buccal, nasal, transmucosal,topical, route, as an ophthalmic formulation, or via inhalation.Transdermal administration may be very desirable for patients who areforgetful or petulant about taking oral medicine. The compound of thepresent invention may also be administered by the percutaneous,intramuscular, intranasal or intrarectal route in particularcircumstances. The route of administration may be varied in any way,depending on the physical properties of the drugs, the convenience ofthe patient and the caregiver, and other relevant conditions(Remington's Pharmaceutical Sciences, 18th Edition, Mack Publishing Co.(1990)).

In another aspect, the present invention provides use of the compound ofthe present invention for simultaneous, separate or sequentialadministration in combination with an additional therapeutic agent (suchas an additional anti-cancer/anti-tumor agent, or an additionalanti-viral agent).

The dosage range of the compound of the present invention or a productcomprising the same (such as a pharmaceutical composition, apharmaceutical formulation, or a dosage form) is 0.1-1000 mg/kg bodyweight per day, preferred dosage range is 1-800 mg/kg body weight perday, preferred dosage range is 10-600 mg/kg body weight per day,particularly preferred dosage range is 100-400 mg/kg body weight perday, and most preferred dosage range is 120-250 mg/kg body weight perday. The exact dosage required for treating a patient may be determinedby a physician in view of the stage and severity of the disease as wellas patient's specific need and response.

Unless otherwise indicated, the term “treating” or “treatment”, as usedherein, means reversing, alleviating, inhibiting the progress of, orpreventing the disorder or condition to which such term applies, or oneor more symptoms of such disorder or condition.

As used herein, the term “mammal” includes a human or non-human animal.An exemplary human subject includes a human subject having a disease ordisorder (such as one described herein) (referred to as a patient), or anormal subject. The term “non-human animal” as used herein includesnon-human primates, livestock and/or domesticated animals, such assheep, dog, cat, cow, pig and the like.

EXAMPLES

The present invention is further described in detail with reference tothe following examples and specific embodiments. However, it should notbe construed that the scope of the present invention is merely limitedto the following examples, technical solutions achieved based on thecontents of the present invention are all within the scope of thepresent invention.

The abbreviations as used herein have the following meanings:

Abbreviation Meaning AcOH acetic acid AcOK potassium acetate Ac₂O aceticanhydride aq. aqueous solution BCl₃ boron trichloride BnBr benzylbromide BzCl benzoyl chloride Bz₂O benzoic anhydride m-CPBAmetachloroperbenzoic acid DAST diethylaminosulfurtrifluoride DCEdichloroethane DCM dichloromethane DMAP 4-dimethylaminopyridine DMFN,N-dimethylformamide DMSO dimethyl sulfoxide Et₃N triethylamine HBrhydrogen bromide HCl hydrochloric acid H₂O water HPLC high-performanceliquid chromatography H₂SO₄ sulphuric acid KF potassium fluoride MeOHmethanol MsCl methylsulfonyl chloride NaBH₄ sodium borohydride NaHsodium hydride Na₂S sodium sulfide NH₃ amonia NaIO₄ sodium periodateNaOMe sodium methoxide SO₂Cl₂ sulfonyl chloride TBAF tetrabutylammoniumfluoride TBDPSCl tert-butyldiphenylchlorosilane TFA trifluoroacetic acidTHF tetrahydrofuran TMSOTf trimethylsilyl triflate

Example 1 Preparation of (S)-ethyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C1) (1) Preparation of1-((2R,3S,4S,5R)-3-fluoro-4-hydroxy-5-(hydroxymethyl)tetrahydrothiophen-2-yl)cytosine(Compound A, i.e. the Core Compound)

(a) SO₂Cl₂, imidazole, DCM; (b) KF, 2-methoxylethanol, reflux; (c) 2MHCl, THF; (d) BzCl, pyridine, DCM; (e) MsCl, pyridine; (f) NaOMe, MeOH;(g) thiourea, MeOH, reflux; (h) AcOK, Ac₂O, AcOH, reflux; (i) 90% TFA;(j) NaIO₄, MeOH, H₂O; (k) HCl, MeOH, reflux; (1) BzCl, pyridine; (m)H₂SO₄, Ac₂O, AcOH; (n) HBr, AcOH, DCM; (o) silylated N-acetylcytosine,80° C.; (p) aq. NH₃, MeOH, HPLC separation.

1-((2R,3S,4S,5R)-3-fluoro-4-hydroxy-5-(hydroxymethyl)tetrahydrothiophen-2-yl)cytosine(Compound A) employed in the present example was prepared by a method ina literature (J. Org. Chem. 1999, 64, 7912-7920).

(2) Preparation of (S)-ethyl2-(((pentafluorophenoxy)(phenoxy)phosphoryl)amino)propanoate (compoundB1)

Phosphorus oxychloride (1.53 g, 10 mmol) was dissolved indichloromethane (10 mL), and was then cooled to −60° C. A solution ofphenol (940 mg, 10 mmol) and triethylamine (1.01 g, 10 mmol) indichloromethane (10 mL) was slowly dropwise added. After stirredovernight at room temperature, the reaction solution was cooled to 0°C., and L-alanine ethyl ester hydrochloride (1.53 g, 10 mmol) was added.After the reaction solution was cooled to −60° C., a solution oftriethylamine (2.02 g, 20 mmol) in dichloromethane (5 mL) was dropwiseadded, and the reaction solution was allowed to warm to roomtemperature. A solution of pentafluorophenol (1.84 g, 10 mmol) andtriethylamine (1.01 g, 10 mmol) in dichloromethane (10 mL) was dropwiseadded to the above solution, which was then stirred at −5° C. for 2 h.After completion of the reaction, the reaction solution was quenched byaddition of water, extracted with ethyl acetate, dried, concentrated andpurified by column chromatography, to give the title compound (CompoundB1).

(3) Preparation of (S)-ethyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C1)

Compound A (260 mg, 1 mmol) was dissolved in anhydrous tetrahydrofuran(50 mL), and air is replaced with argon for three times.Tert-Butylmagnesium chloride (1.0 mol/L, 1.2 mL, 1.2 mmol) was dropwiseadded at −10° C. The reaction mixture was stirred for 2 h, and reactedfor 0.5 h after being warmed to room temperature. A solution of anintermediate, compound B1, (0.53 g, 1.2 mmol), in anhydrous THF (10 mL)was dropwise added. The reaction was conducted at 30° C. for 15 h, thenquenched by dropwise addition of methanol (10 mL), concentrated andpurified by column chromatography, to give compound C1.

The data for structural characterization of the compound are as follows.

ESI-MS: 517.7 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.86 (d, J=3.4 Hz, 1H), 7.38 (t, J=7.6 Hz,2H), 7.31-7.17 (m, 5H), 6.56 (dd, J=4 Hz, 14 Hz, 1H), 6.09-6.03 (m, 2H),5.77 (d, J=7.6 Hz, 1H), 5.03-4.87 (m, 2H), 4.36-4.32 (m, 2H), 4.14-4.12(m, 3H), 3.80-3.78 (m, 1H), 1.28-1.23 (m, 6H).

Example 2 Preparation of (S)-benzyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C2)

Compound C2 was prepared according to a method similar to that ofExample 1, using phosphorus oxychloride, phenol, L-alanine benzyl esterhydrochloride, pentafluorophenol, and Compound A as starting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 579.6 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.86 (d, J=3.4 Hz, 1H), 7.38 (t, J=7.6 Hz,2H), 7.31-7.17 (m, 10H), 6.56 (dd, J=4 Hz, 14 Hz, 1H), 6.09-6.03 (m,2H), 5.77 (d, J=7.6 Hz, 1H), 5.36 (s, 2H), 5.03-4.87 (m, 2H), 4.36-4.32(m, 2H), 4.14-4.12 (m, 1H), 3.80-3.78 (m, 1H), 1.23 (d, J=6.4 Hz, 3H).

Example 3 Preparation of (S)-phenyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C3)

Compound C3 was prepared according to a method similar to that ofExample 1, using phosphorus oxychloride, phenol, L-alanine phenyl esterhydrochloride, pentafluorophenol, and Compound A as starting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 565.1 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.86 (d, J=3.4 Hz, 1H), 7.38 (t, J=7.6 Hz,2H), 7.31-7.17 (m, 10H), 6.56 (dd, J=4 Hz, 14 Hz, 1H), 6.09-6.03 (m,2H), 5.77 (d, J=7.6 Hz, 1H), 5.03-4.87 (m, 2H), 4.36-4.32 (m, 2H),4.14-4.12 (m, 1H), 3.80-3.78 (m, 1H), 1.23 (d, J=6.4 Hz, 3H).

Example 4 Preparation of (S)-isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(4-fluorophenoxy)phosphoryl)amino)propanoate(C4) (1) Preparation of (S)-isopropyl2-(((pentafluorophenoxy)(4-fluorophenoxy)phosphoryl)amino)propanoate

Phosphorus oxychloride (1.53 g, 10 mmol) was dissolved indichloromethane (10 mL), and was then cooled to −60° C. A solution of4-fluorophenol (1.12 g, 10 mmol) and triethylamine (1.01 g, 10 mmol) indichloromethane (10 mL) was slowly dropwise added. After stirredovernight at room temperature, the reaction solution was cooled to 0°C., and L-alanine isopropyl ester hydrochloride (1.53 g, 10 mmol) wasadded. After the reaction solution was cooled to −60° C., a solution oftriethylamine (2.02 g, 20 mmol) in dichloromethane (5 mL) was dropwiseadded, and the reaction solution was allowed to warm to roomtemperature. A solution of pentafluorophenol (1.84 g, 10 mmol) andtriethylamine (1.01 g, 10 mmol) in dichloromethane (10 mL) was dropwiseadded to the above solution, which was then stirred at −5° C. for 2 h.After completion of the reaction, the reaction solution was quenched byaddition of water, extracted with ethyl acetate, dried, concentrated andpurified by column chromatography, to give the title compound.

(2) Preparation of (S)-isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(4-fluorophenoxy)phosphoryl)amino)propanoate (C4)

Compound A (260 mg, 1 mmol) was dissolved in anhydrous tetrahydrofuran(50 mL), and air is replaced with argon for three times.Tert-Butylmagnesium chloride (1.0 mol/L, 1.2 mL, 1.2 mmol) was dropwiseadded at −10° C. The reaction mixture was stirred for 2 h, and reactedfor 0.5 h after being warmed to room temperature. A solution of(S)-isopropyl2-(((pentafluorophenoxy)(4-fluorophenoxy)phosphoryl)amino)propanoate(566 mg, 1.2 mmol) in anhydrous THF (10 mL) was dropwise added. Thereaction was conducted at 30° C. for 15 h, then quenched by dropwiseaddition of methanol (10 mL), concentrated and purified by columnchromatography, to give compound C4.

The data for structural characterization of the compound are as follows.

ESI-MS: 549.3 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) (δ 7.86 (d, J=3.4 Hz, 1H), 7.38 (t, J=7.6 Hz,2H), 7.35-7.17 (m, 4H), 6.56 (dd, J=4 Hz, 14 Hz, 1H), 6.09-6.03 (m, 2H),5.77 (d, J=7.6 Hz, 1H), 5.03-4.87 (m, 2H), 4.36-4.32 (m, 2H), 4.14-4.12(m, 1H), 3.80-3.78 (m, 1H), 1.23 (d, J=6.4 Hz, 3H).

Example 5 Preparation of (S)-isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(4-chlorophenoxy)phosphoryl)amino)propanoate(C5)

Compound C5 was prepared according to a method similar to that ofExample 1, using phosphorus oxychloride, 4-chlorophenol, L-alanineisopropyl ester hydrochloride, pentafluorophenol, and Compound A asstarting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 565.4 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) (δ 7.86 (d, J=3.4 Hz, 1H), 7.38 (t, J=7.6 Hz,2H), 7.30-7.17 (m, 4H), 6.56 (dd, J=4 Hz, 14 Hz, 1H), 6.09-6.03 (m, 2H),5.77 (d, J=7.6 Hz, 1H), 5.03-4.87 (m, 2H), 4.36-4.32 (m, 2H), 4.14-4.12(m, 1H), 3.80-3.78 (m, 1H), 1.23 (d, J=6.4 Hz, 3H).

Example 6 Preparation of (S)-isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(4-bromophenoxy)phosphoryl)amino)propanoate(C6)

Compound C6 was prepared according to a method similar to that ofExample 1, using phosphorus oxychloride, 4-bromophenol, L-alanineisopropyl ester hydrochloride, pentafluorophenol, and Compound A asstarting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 611.2 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.86 (d, J=3.4 Hz, 1H), 7.38 (t, J=7.6 Hz,2H), 7.28-7.17 (m, 4H), 6.56 (dd, J=4 Hz, 14 Hz, 1H), 6.09-6.03 (m, 2H),5.77 (d, J=7.6 Hz, 1H), 5.03-4.87 (m, 2H), 4.36-4.32 (m, 2H), 4.14-4.12(m, 1H), 3.80-3.78 (m, 1H), 1.23 (d, J=6.4 Hz, 3H).

Example 7 Preparation of isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)-2-methylpropanoate(C₇) (1) Preparation of isopropyl2-methyl-2-(((pentafluorophenoxy)(phenoxy)phosphoryl)amino)propanoate

Phosphorus oxychloride (1.53 g, 10 mmol) was dissolved indichloromethane (10 mL), and was then cooled to −60° C. A solution ofphenol (1.12 g, 10 mmol) and triethylamine (1.01 g, 10 mmol) indichloromethane (10 mL) was slowly dropwise added. After stirredovernight at room temperature, the reaction solution was cooled to 0°C., and 2-methyl-alanine isopropyl ester hydrochloride (1.82 g, 10 mmol)was added. After the reaction solution was cooled to −60° C., a solutionof triethylamine (2.02 g, 20 mmol) in dichloromethane (5 mL) wasdropwise added, and the reaction solution was allowed to warm to roomtemperature. A solution of pentafluorophenol (1.84 g, 10 mmol) andtriethylamine (1.01 g, 10 mmol) in dichloromethane (10 mL) was dropwiseadded to the above solution, which was then stirred at −5° C. for 2 h.After completion of the reaction, the reaction solution was quenched byaddition of water, extracted with ethyl acetate, dried, concentrated andpurified by column chromatography, to give the title compound.

(2) Preparation of isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)-2-methylpropanoate(C7)

Compound A (260 mg, 1 mmol) was dissolved in anhydrous tetrahydrofuran(50 mL), and air is replaced with argon for three times.Tert-Butylmagnesium chloride (1.0 mol/L, 1.2 mL, 1.2 mmol) was dropwiseadded at −10° C. The reaction mixture was stirred for 2 h, and reactedfor 0.5 h after being warmed to room temperature. A solution ofisopropyl2-methyl-2-(((pentafluorophenoxy)(phenoxy)phosphoryl)amino)propanoate(582 mg, 1.2 mmol) in anhydrous THF (10 mL) was dropwise added. Thereaction was conducted at 30° C. for 15 h, then quenched by dropwiseaddition of methanol (10 mL), concentrated and purified by columnchromatography, to give compound C7.

The data for structural characterization of the compound are as follows.

ESI-MS: 545.5 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.86 (d, J=3.4 Hz, 1H), 7.38 (t, J=7.6 Hz,2H), 7.31-7.17 (m, 5H), 6.56 (dd, J=4 Hz, 14 Hz, 1H), 6.09-6.03 (m, 2H),5.77 (d, J=7.6 Hz, 1H), 5.03-4.87 (m, 2H), 4.36-4.32 (m, 2H), 4.14-4.12(m, 1H), 1.27 (s, 6H), 1.17 (d, J=5.2 Hz, 6H).

Example 8 Preparation of (S)-isopropyl2-(((S)-(((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C8)

(S)-isopropyl2-(((S)-(pentafluorophenoxy)(phenoxy)phosphoryl)amino)propanoateemployed in the present invention was prepared by a method in aliterature (J. Org. Chem. 2011, 76, 8311-8319).

Compound C8 was prepared according to a method similar to that ofExample 1, using (S)-isopropyl2-(((S)-(pentafluorophenoxy)(phenoxy)phosphoryl)amino)propanoate, andCompound A as starting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 531.1 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.86 (d, J=3.4 Hz, 1H), 7.38 (t, J=7.6 Hz,2H), 7.31-7.17 (m, 5H), 6.56 (dd, J=4 Hz, 14 Hz, 1H), 6.09-6.03 (m, 2H),5.77 (d, J=7.6 Hz, 1H), 5.03-4.87 (m, 2H), 4.36-4.32 (m, 2H), 4.14-4.12(m, 1H), 3.80-3.78 (m, 1H), 1.23 (d, J=6.4 Hz, 3H), 1.17 (d, J=5.2 Hz,6H).

Example 9 Preparation of (S)-isopropyl2-(((S)-(((2R,3S,4S,5R)-5-(4-amino-5-fluoro-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C9)

1-((2R,3S,4S,5R)-3-fluoro-4-hydroxy-5-(hydroxymethyl)tetrahydrothiophen-2-yl)-5-fluorocytosineemployed in the present invention was prepared by a method in aliterature (Bioorg. Med. Chem. 2000, 8, 1545-1558).

Compound C9 was prepared according to a method similar to that ofExample 1, using (S)-isopropyl2-(((S)-(pentafluorophenoxy)(phenoxy)phosphoryl)amino)propanoate, and1-((2R,3S,4S,5R)-3-fluoro-4-hydroxy-5-(hydroxymethyl)tetrahydrothiophen-2-yl)-5-fluorocytosineas starting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 549.5 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 8.23 (d, J=7.3 Hz, 1H), 7.38-7.31 (m, 3H),7.23-7.16 (m, 5H), 6.52 (dd, J=4 Hz, 14 Hz, 1H), 6.05-6.03 (m, 2H),5.03-4.87 (m, 2H), 4.36-4.32 (m, 2H), 4.14-4.12 (m, 1H), 3.80-3.78 (m,1H), 1.25 (d, J=6.4 Hz, 3H), 1.14 (d, J=5.2 Hz, 6H).

Example 10 Preparation of (S)-isopropyl2-(((S)-(((2R,3S,4S,5R)-5-(6-amino-2-chloro-9H-purin-9-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C10)

(2R,3S,4S,5R)-5-(6-amino-2-chloro-9H-purin-9-yl)-4-fluoro-2-(hydroxymethyl)tetrahydrothiophen-3-olemployed in the present invention was prepared by a method in aliterature (Bioorg. Med. Chem. 2000, 8, 1545-1558).

Compound C10 was prepared according to a method similar to that ofExample 1, using (S)-isopropyl2-(((S)-(pentafluorophenoxy)(phenoxy)phosphoryl)amino)propanoate, and(2R,3S,4S,5R)-5-(6-amino-2-chloro-9H-purin-9-yl)-4-fluoro-2-(hydroxymethyl)tetrahydrothiophen-3-olas starting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 589.4 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 8.42 (s, 1H), 7.32-7.15 (m, 8H), 6.50 (dd,J=4 Hz, 14 Hz, 1H), 6.07-6.03 (m, 2H), 5.72 (d, J=7.6 Hz, 1H), 5.01-4.87(m, 2H), 4.37-4.32 (m, 2H), 4.15-4.12 (m, 1H), 3.80-3.78 (m, 1H), 1.24(d, J=6.4 Hz, 3H), 1.15 (d, J=5.2 Hz, 6H).

Example 11 Preparation of (S)-isopropyl2-(((S)-(((2R,3S,4S,5R)-5-(4-(2-propylpentanamido)-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C11)

Compound C8 (53 mg, 0.1 mmol) and ethyldiisopropylamine (26 mg, 0.2mmol) was dissolved in dry dichloromethane (2 mL). 2-propylpentanoylchloride (17 mg, 0.1 mmol) was added at 0° C. The reaction mixture waswarmed to room temperature, and stirred overnight. The reaction mixturewas quenched by addition of saturated NaHCO₃, extracted with ethylacetate, dried, concentrated, and purified by column chromatography, togive compound C11.

The data for structural characterization of the compound are as follows.

ESI-MS: 657.7 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.86 (d, J=3.4 Hz, 1H), 7.38 (t, J=7.6 Hz,2H), 7.31-7.17 (m, 5H), 6.56 (dd, J=4 Hz, 14 Hz, 1H), 6.09-6.03 (m, 2H),5.77 (d, J=7.6 Hz, 1H), 5.03-4.87 (m, 2H), 4.36-4.32 (m, 2H), 4.14-4.12(m, 1H), 3.80-3.78 (m, 1H), 2.50-2.47 (m, 1H), 1.43-1.22 (m, 17H),0.94-0.91 (m, 6H).

Example 12 Preparation of (S)-isopropyl2-(((S)-(((2R,3S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4,4-difluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C12) (1) Preparation of1-((2R,4S,5R)-3,3-difluoro-4-hydroxy-5-(hydroxymethyl)tetrahydrothiophen-2-yl)cytosine

(a) BnBr, NaH, DMF, THF; (b) 2M HCl, THF; (c) NaIO₄, H₂O, MeOH; (d)NaBH₄, MeOH; (e) 5% HCl/MeOH; (f) MsCl, pyridine; (g) Na₂S, DMF, 100°C.; (h) 4M HCl, THF; (i) NaBH₄, MeOH; (j) TBDPSCl, imidazole, DMF; (k)Ac₂O, DMSO; (1) DAST, DCM; (m) BCl₃, DCM, −78° C.; (n) Bz₂O, Et₃N, DMAP,CH₃CN; (o) m-CPBA, DCM, −78° C.; (p) silylated N-acetylcytosine, TMSOTf,DCE, 0° C.; (q) TBAF, THF; (r) aq. NH₃, MeOH, HPLC separation.

1-((2R,4S,5R)-3,3-difluoro-4-hydroxy-5-(hydroxymethyl)tetrahydrothiophen-2-yl)cytosineemployed in the present invention was prepared by a method in aliterature (J. Org. Chem. 1997, 62, 3140-3152).

(2) Compound C12 was Prepared According to a Method Similar to that ofExample 1, Using (S)-isopropyl2-(((S)-(pentafluorophenoxy)(phenoxy)phosphoryl)amino)propanoate, and1-((2R,4S,5R)-3,3-difluoro-4-hydroxy-5-(hydroxymethyl)tetrahydrothiophen-2-yl)cytosineas Starting Materials

The data for structural characterization of the compound are as follows.

ESI-MS: 549.5 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.96 (d, J=3.4 Hz, 1H), 7.35 (m, 3H),7.23-7.17 (m, 5H), 6.46 (dd, J=4 Hz, 14 Hz, 1H), 5.98-5.95 (m, 2H), 5.84(d, J=7.6 Hz, 1H), 5.35 (brs, 1H), 4.36-4.32 (m, 2H), 4.17-4.14 (m, 1H),3.85-3.80 (m, 1H), 1.13 (d, J=6.4 Hz, 3H), 1.09 (d, J=5.2 Hz, 6H).

Examples 13 and 14 Preparation of (S)-isopropyl2-(((S)-(((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(benzo[d][1,3]dioxol-5-yloxy)phosphoryl)amino)propanoate(C14) and (S)-isopropyl2-(((R)-(((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(benzo[d][1,3]dioxol-5-yloxy)phosphoryl)amino)propanoate(C13) (1) Preparation of (S)-isopropyl2-(((pentafluorophenoxy)(benzo[d][1,3]dioxol-5-yloxy)phosphoryl)amino)propanoate

Phosphorus oxychloride (1.53 g, 10 mmol) was dissolved indichloromethane (10 mL), and was then cooled to −60° C. A solution ofsesamol (1.38 g, 10 mmol) and triethylamine (1.01 g, 10 mmol) indichloromethane (10 mL) was slowly dropwise added. After stirredovernight at room temperature, the reaction solution was cooled to 0°C., and L-alanine isopropyl ester hydrochloride (1.53 g, 10 mmol) wasadded. After the reaction solution was cooled to −60° C., a solution oftriethylamine (2.02 g, 20 mmol) in dichloromethane (5 mL) was dropwiseadded, and the reaction solution was allowed to warm to roomtemperature. A solution of pentafluorophenol (1.84 g, 10 mmol) andtriethylamine (1.01 g, 10 mmol) in dichloromethane (10 mL) was dropwiseadded to the above solution, which was then stirred at −5° C. for 2 h.After completion of the reaction, the reaction solution was quenched byaddition of water, extracted with ethyl acetate, dried, concentrated andpurified by column chromatography, to give the title compound.

(2) Preparation of (S)-isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(benzo[d][1,3]dioxol-5-yloxy)phosphoryl)amino)propanoate

Compound A (260 mg, 1 mmol) was dissolved in anhydrous tetrahydrofuran(50 mL), and air is replaced with argon for three times.Tert-Butylmagnesium chloride (1.0 mol/L, 1.2 mL, 1.2 mmol) was dropwiseadded at −10° C. The reaction mixture was stirred for 2 h, and reactedfor 0.5 h after being warmed to room temperature. A solution of(S)-isopropyl2-(((pentafluorophenoxy)(benzo[d][1,3]dioxol-5-yloxy)phosphoryl)amino)propanoate(596 mg, 1.2 mmol) in anhydrous THF (10 mL) was dropwise added. Thereaction was conducted at 30° C. for 15 h, then quenched by dropwiseaddition of methanol (10 mL), concentrated and purified by columnchromatography, to give the title compound.

(3) Preparation of (S)-isopropyl2-(((S)-(((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(benzo[d][1,3]dioxol-5-yloxy)phosphoryl)amino)propanoate(C14) and (S)-isopropyl2-(((R)-(((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(benzo[d][1,3]dioxol-5-yloxy)phosphoryl)amino)propanoate(C13)

The mixture of the diastereomers obtained in the previous step wasseparated by preparative HPLC using the following separation conditions:octadecyl bonded silica gel was used as filler (20×250 mm, 5 μm), columntemperature was 40° C., flow rate was 10.0 mL/min, detection wavelengthwas 220 nm, mobile phase A was water (neutral), mobile phase B wasmethanol, and linear gradient elution was performed. The first main peakwas collected, and freeze-dried to obtain (S)-isopropyl2-(((R)-(((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(benzo[d][1,3]dioxol-5-yloxy)phosphoryl)amino)propanoate(C13), 17 mg; and the second main peak was collected, and freeze-driedto obtain (S)-isopropyl2-(((S)-(((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(benzo[d][1,3]dioxol-5-yloxy)phosphoryl)amino)propanoate(C14), 30 mg.

The data for structural characterization of the compound are as follows.

ESI-MS: 575.2 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.93 (d, J=8 Hz, 1H), 7.75 (bs, 1H), 7.46(bs, 1H), 6.88-6.83 (m, 2H), 6.67-6.65 (m, 1H), 6.51 (d, J=8 Hz, 1H),5.76 (d, J=7.6 Hz, 1H), 4.90-4.86 (m, 4H), 4.31 (bs, 2H), 4.13-4.11 (m,1H), 3.78-3.76 (m, 1H), 3.50 (bs, 1H), 1.23 (d, J=6.4 Hz, 3H), 1.16 (d,J=5.2 Hz, 6H).

³¹P NMR (DMSO-d₆, 162 MHz) δ 4.59.

The data for structural characterization of the compound are as follows.

ESI-MS: 575.2 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) (δ 7.93 (d, J=8 Hz, 1H), 7.75 (bs, 1H), 7.46(bs, 1H), 6.88-6.83 (m, 2H), 6.67-6.65 (m, 1H), 6.51 (d, J=8 Hz, 1H),5.76 (d, J=7.6 Hz, 1H), 4.90-4.86 (m, 4H), 4.31 (bs, 2H), 4.13-4.11 (m,1H), 3.78-3.76 (m, 1H), 3.50 (bs, 1H), 1.23 (d, J=6.4 Hz, 3H), 1.16 (d,J=5.2 Hz, 6H). ³¹P NMR (DMSO-d₆, 162 MHz) (δ 4.50.

Example 15 Preparation of (2S)-4-fluorobenzyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(phenoxy)phosphoryl)amino)propanoate(C15)

Compound C15 was prepared according to a method similar to that ofExample 1, using phosphorus oxychloride, phenol, L-alanine4-fluorobenzyl ester hydrochloride, pentafluorophenol, and Compound A asstarting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 597.2 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.86 (d, J=8 Hz, 1H), 7.67-7.17 m, 12H),6.54 (dd, J=4 Hz, 14 Hz, 1H), 6.21-6.15 (m, 1H), 6.07 (bs, 1H), 5.78 (d,J=4 Hz, 1H), 5.11 (bs, 2H), 4.31 (bs, 2H), 4.12-4.10 (m, 1H), 3.94-3.92(m, 1H), 3.47 (bs, 1H), 1.26 (d, J=8 Hz, 3H).

³¹P NMR (DMSO-d₆, 162 MHz) δ 4.02.

Example 16 (S)-isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)((2,3-dihydrobenzo[b][1,4]dioxin-5-yl)oxy)phosphoryl)amino)propanoate(C16)

Compound C16 was prepared according to a method similar to that ofExample 1, using phosphorus oxychloride,5-hydroxy-2,3-dihydrobenzo[1,4]dioxine, L-alanine isopropyl esterhydrochloride, pentafluorophenol, and Compound A as starting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 589.2 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) (δ 7.93 (d, J=8 Hz, 1H), 7.34 (bs, 1H), 7.26(bs, 1H), 6.91-6.89 (m, 1H), 6.81-6.73 (m, 1H), 6.61-6.56 (m, 1H),6.11-6.07 (m, 1H), 6.01-5.85 (m, 1H), 5.80-5.75 (m, 1H), 5.04-4.82 (m,1H), 4.37-4.17 (m, 7H), 3.87-3.83 (m, 1H), 3.50 (bs, 1H), 1.23 (d, J=6.4Hz, 3H), 1.16 (d, J=5.2 Hz, 6H).

³¹P NMR (DMSO-d₆, 162 MHz) δ 4.58.

Example 17 (S)-isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)((7-fluoro-2,3-dihydrobenzofuran-4-yl)oxy)phosphoryl)amino)propanoate(C17)

Compound C17 was prepared according to a method similar to that ofExample 1, using phosphorus oxychloride,4-hydroxy-7-fluoro-2,3-dihydrobenzofuran, L-alanine isopropyl esterhydrochloride, pentafluorophenol, and Compound A as starting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 591.2 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) (δ 7.89 (d, J=8 Hz, 1H), 7.37 (bs, 1H), 7.29(bs, 1H), 7.10-7.06 (m, 1H), 6.76-6.73 (m, 1H), 6.60-6.54 (m, 1H),6.15-6.10 (m, 2H), 5.81-5.78 (m, 1H), 5.10-4.90 (m, 2H), 4.72-4.61 (m,3H), 4.36-4.34 (m, 2H), 4.25-4.20 (m, 1H), 3.78-3.75 (m, 1H), 3.53-3.50(m, 3H), 3.38-3.35 (m, 2H), 1.23 (d, J=6.4 Hz, 3H), 1.16 (d, J=5.2 Hz,6H).

³¹P NMR (DMSO-d₆, 162 MHz) δ 4.65.

Example 18

(S)-isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)((2,3-dihydrobenzofuran-6-yl)oxy)phosphoryl)amino)propanoate(C18)

Compound C18 was prepared according to a method similar to that ofExample 1, using phosphorus oxychloride,6-hydroxy-2,3-dihydrobenzofuran, L-alanine isopropyl esterhydrochloride, pentafluorophenol, and Compound A as starting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 573.2 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.89 (d, J=8 Hz, 1H), 7.35 (bs, 1H), 7.26(bs, 1H), 7.20-7.18 (m, 1H), 6.68-6.66 (m, 2H), 6.59-6.56 (m, 1H),6.08-6.03 (m, 1H), 5.80-5.79 (m, 1H), 5.02-4.88 (m, 2H), 4.57 (t, J=8Hz, 3H), 4.60-4.55 (m, 2H), 4.36-4.32 (m, 1H), 3.80-3.75 (m, 1H), 3.47(bs, 1H), 3.17-3.13 (m, 2H), 1.23 (d, J=6.4 Hz, 3H), 1.16 (d, J=5.2 Hz,6H).

³¹P NMR (DMSO-d₆, 162 MHz) δ 4.20.

Example 19 (S)-isopropyl2-(((((2R,3S,4S,5R)-5-(4-amino-2-oxopyrimidin-1(2H)-yl)-4-fluoro-3-hydroxytetrahydrothiophen-2-yl)methoxy)(benzofuran-6-yloxy)phosphoryl)amino)propanoate(C19)

Compound C19 was prepared according to a method similar to that ofExample 1, using phosphorus oxychloride, 6-hydroxy-benzofuran, L-alanineisopropyl ester hydrochloride, pentafluorophenol, and Compound A asstarting materials.

The data for structural characterization of the compound are as follows.

ESI-MS: 571.2 (M+1)

¹H NMR (DMSO-d₆, 400 MHz) δ 7.89 (d, J=8 Hz, 1H), 7.54 (s, 1H), 7.35(bs, 1H), 7.26 (bs, 1H), 7.20-7.18 (m, 1H), 6.68-6.66 (m, 3H), 6.59-6.56(m, 1H), 6.08-6.03 (m, 1H), 5.80-5.79 (m, 1H), 5.02-4.88 (m, 2H),4.60-4.55 (m, 3H), 4.36-4.32 (m, 1H), 3.80-3.75 (m, 1H), 3.47 (bs, 1H),1.23 (d, J=6.4 Hz, 3H), 1.16 (d, J=5.2 Hz, 6H).

³¹P NMR (DMSO-d₆, 162 MHz) δ 4.35.

Biological Assays

Experimental Example 1: In Vitro Experiment

This experimental example was used for the evaluation of theeffectiveness of the compounds of the present invention in inhibitingthe proliferation of human gastric cancer NCI-N87, colorectal cancerHCT-116, colorectal cancer HCT-15, and pancreatic cancer BxPC-3 celllines.

1. Cells for the Experiment

The tumor cell lines employed in the present experiment were gastriccancer cell NCI-N87 (obtained from Guangzhou Jennio BiologicalTechnology Co., Ltd.), colorectal cancer cell HCT-116 (obtained fromChengdu Center for Safety Evaluation of Drugs), colorectal cancer cellHCT-15 and pancreatic cancer cell BxPC-3 (both obtained from ATCC, US).

The above cell lines were cultured as a monolayer in vitro, and theculture conditions were as follows. Each of the cell lines is culturedin a corresponding culture medium (RPMI-1640, IMDM and L-15 culturemedium (manufacturer: Gibco)) supplemented with 10% heat inactivatedFetal Bovine Serum (manufacturer: Sigma), in an incubator at 37° C. and5% CO₂. The cells were subcultured by treatment with trypsin-EDTAdigestion.

2. Sample Preparation

For each type of tumor cells, a blank group, a vehicle group (containing1‰ DMSO) and 8 groups with a test compound at concentrations of 5 nM, 10nM, 50 nM, 100 nM, 500 nM, 1000 nM, 5000 nM, and 10000 nM (with eachconcentration in triplicate) were set.

Appropriate amounts of test compounds were weighted, and dissolved inDMSO (cell culture grade, Sigma) to prepare stock solutions of variousconcentration gradients according to desired concentrations. Duringincubation, they were diluted by 1000 times as necessary, and incubationsolutions with various drug concentrations were prepared (compound stocksolution: medium containing 2% FBS=1:1000).

3. Experimental Method

The experiment was performed according to a CCK-8 method as describedbelow. Cancer cells to be tested were seeded in a 96-well culture plateat a concentration of 5˜10×10⁴/mL (100 μL/well), followed by incubationat 37° C. and 5% CO₂ for 24 h. The medium was discarded, and incubationsolutions with different drug concentrations (200 μL) were respectivelyadded to each well, and the cells were further incubated for 72 h. Afterthe incubation, a CCK-8 solution (20 μL/well) was added to each well tobe tested, and the incubation was continued for 4 h in the incubator. ODvalues at two wavelengths (Detection wavelength: 450 nm, and referencewavelength: 650 nm) were determined on a multifunctional fully-automaticmicroplate reader.

The inhibitory rate of tumor cell growth was calculated according to thefollowing formula:

Inhibitoryrate=[(OD_(vehicle)−OD_(blank))−(OD_(drug)−OD_(blank))]/(OD_(vehicle)−OD_(blank))*100%

Based on the inhibitory rate, a concentration-inhibitory rate curve wasfit using GraphPad prism 5.0 software, and IC₅₀ was calculated.

FIG. 1 shows that the compound of Example 8 (C8) has potent inhibitoryeffects on gastric cancer cell NCI-N87, colorectal cancer cell HCT-116,colorectal cancer cell HCT-15, and pancreatic cancer cell BxPC-3 at theabove 8 concentrations. IC₅₀ values of example compounds of the presentinvention for each type of cancer cells are shown in table 1-1 to 1-4.

TABLE 1-1 IC₅₀ (μM) Compound gastric cancer cell NCI-N87 C2 0.25 C80.483 C13 0.55 C14 0.18 C15 0.24 C16 0.30 C17 0.63 C19 0.35

TABLE 1-2 IC₅₀ (μM) Compound colorectal cancer cell HCT-116 C8 0.485

TABLE 1-3 IC₅₀ (μM) Compound colorectal cancer cell HCT-15 C2 2.97 C81.964 C14 9.78 C15 4.08

TABLE 1-4 IC₅₀ (μM) Compound pancreatic cancer cell BxPC-3 C2 1.28 C80.705 C14 2.82 C15 1.80 C16 1.15 C17 3.80 C18 2.74 C19 0.68

According to the experimental results, the IC₅₀ values of the compoundsof the present invention were in the range of 0.1-1 μM for gastriccancer cell NCI-N87, in the range of 0.1-1 μM for colorectal cancer cellHCT-116, in the range of 0.5-10 μM for colorectal cancer cell lineHCT-15, and in the range of 0.1-5 μM for pancreatic cancer cell BxPC-3.As such, the compounds of the present invention have inhibitory activityon tumor cells.

The compound of Example 8 (C8) of the present invention has a potentanti-tumor effect in vitro, and has excellent inhibitory effects ongastric cancer cell NCI-N87, colorectal cancer cell HCT-116, colorectalcancer cell HCT-15, and pancreatic cancer cell BxPC-3. The compounds ofExamples 2, 14 and 15 each have excellent inhibitory effects on gastriccancer cell NCI-N87, colorectal cancer cell HCT-15, and pancreaticcancer cell BxPC-3. The compounds of Examples 16, 17 and 19 haveexcellent inhibitory effects on gastric cancer cell NCI-N87 andpancreatic cancer cell BxPC-3. The compound of Example 13 has anexcellent inhibitory effect on gastric cancer cell NCI-N87, and thecompound of Example 18 has an excellent inhibitory effect on pancreaticcancer cell BxPC-3.

Experimental Example 2: In Vivo Activity Test

This experimental example was used for the evaluation of theeffectiveness of the compounds of the present invention in inhibitingthe proliferation of a subcutaneous xenograft of human tumor cells viavarious routes of administration.

As an example, the present experimental example investigated variationsin tumor volume and body weight of mice with subcutaneous xenografts ofhuman colorectal cancer cell line HCT-116 and gastric cancer cell lineNCI-N87 after compound C8 was administered via various routes, so as todetermine the pharmacological efficacy and toxicity of each test sampleon mice bearing a tumor of colorectal cancer cell HCT-116 or gastriccancer cell NCI-N87.

1. Cell Lines for the Test

Gastric cancer cell NCI-N87 and colorectal cancer cell HCT-116 werecultured as a monolayer in vitro, and the culture conditions wereRPMI-1640 culture medium supplemented with 10% heat inactivated FetalBovine Serum, and incubation in an incubator at 37° C. and 5% CO₂. Thecells were subcultured by treatment with trypsin-EDTA digestion.

2. Tumor Cell Inoculation and Grouping of Animals

The tumor cells were respectively inoculated into BALB/c nude mice (SPFgrade, female, 16-18 g per mouse, about 6 to 8 weeks old, Beijing VitalRiver Laboratory Animal Technology Co., Ltd.).

Each nude mouse was inoculated with about 2.5×10⁶ HCT-116 tumor cells orabout 3×10⁶ NCI-N87 tumor cells (suspended in 0.1 ml PBS) subcutaneouslyinto the underarm of the right flank. After the inoculated tumor reacheda size in the range of about 100-200 mm³, nude mice bearing a tumor thatis too small (smaller than 100 mm³) or too big (bigger than 200 mm³)were removed from the study, and the remaining ones were randomized intogroups.

3. Sample Preparation

Sulfobutyl ether-β-cyclodextrin (SE-β-CD) was formulated withphysiological saline to form a 10% solution, which was then filteredthrough a 0.22 μm sterile filter for later use.

An appropriate amount of the test compound was weighted, and added inDMSO. The resultant solution was vortexed to uniformity, and the 10%solution of SE-β-CD was added according to the desired concentration.The solution was vortexed to uniformity, and the final concentration ofDMSO was adjusted to 5%. A gemcitabine injection (a positive control)was directly diluted to the desired concentration with physiologicalsaline. A 10% solution of SE-β-CD containing 5% DMSO was prepared as avehicle control.

4. Test Method

Mice bearing a tumor having a volume of about 100-200 mm³ were selected,and randomized into 5 groups (8 mice per group). The dosing volume was10 mL/kg, and the administration (intravenous administration (i.v.) ororal administration (p.o.)) was performed twice a week for 3 weeks. Thetumor volume and body weight were measured twice a week after theadministration, and the mortality of animals was observed every day.

5. Test Indexes

5.1 Tumor Volume

The diameter of a tumor was measured, and the tumor volume wascalculated according to the following formula: V=0.5a×b², wherein a andb respectively represent the major and minor diameters of a tumor. Theanti-tumor effect was evaluated by the tumor growth inhibition (TGI)(%).

TGI (%)=[1−(V _(T-end) −V _(T-start))/(V _(C-end) −V _(C-start))]*100%

wherein:

V_(T-end): the mean value of tumor volume of a treatment group at theend of the test;

V_(T-start): the mean value of tumor volume of a treatment group at thebeginning of the test;

V_(C-end): the mean value of tumor volume of a vehicle group at the endof the test;

and

V_(C-start): the mean value of tumor volume of a vehicle group at thebeginning of the test.

5.2 Body Weight: The Body Weight of an Animal was Measured Twice a Week.

6. Test Results

6.1 the Effects on Gastric Cancer Cell NCI-N87

6.1.1 Tumor Regression

Compared with the vehicle control group and the positive control(gemcitabine injection) group, in the groups treated with C8 samples,the tumor growth was significantly inhibited, and various routes ofadministration of C8 were shown to be safe and well tolerated.

The results of TGI and tumor regression of each group are shown in Table2.

The results indicated that in the groups treated with C8, complete tumorregression occurred in all the animals, while in the group treated witha gemcitabine injection, complete tumor regression occurred in 2animals, and partial tumor regression occurred in 6 animals.

TABLE 2 the results of TGI and tumor regression in a model of gastriccancer cell NCI-N87. Adminis- Dosage tration TGI Tumor Group Compound(μmol/kg) route (%) regression 1 Vehicle control — i.v. / 0 2Gemcitabine 190 i.v. 107 2/8 CR, 6/8 PR 4 Compound C8 190 i.v. 109 8/8CR 5 Compound C8 190 p.o. 110 8/8 CR Note: CR represents complete tumorregression; PR represents partial tumor regression, i.e., the tumorvolume is smaller than that at the beginning of the administration; i.v.represents intravenous administration; and p.o. represents oraladministration.

6.1.2 Body Weight Change and Mortality of the Animals

At the end of the observation (which was continued for 14 days after thelast administration), the body weight of the animals increased in allthe groups compared with the weight at the beginning of theadministration, and no animal deaths occurred in each group. The resultsare shown in Table 3.

TABLE 3 body weight change and mortality of the animals in each groupAdminis- Dosage tration Body weight Group Compound (μmol/kg) routechange 1 Vehicle control — i.v. +11.9% 2 Gemcitabine injection 190 i.v.+4.8% 4 Compound C8 190 i.v. +8.1% 5 Compound C8 190 p.o. +8.1%

On the one hand, in the test on mice bearing a tumor of gastric cancercell line NCI-N87, compared with the vehicle control group, in the grouptreated with a gemcitabine injection, complete tumor regression occurredin 2 animals, and partial tumor regression occurred in 6 animals; whilecomplete tumor regression occurred in all the animals from the groupstreated with intravenous administration and oral administration of C8,indicating that the tumor growth in animals from groups treated with C8(i.v. and p.o.) was significantly inhibited.

On the other hand, no animal death occurred in any of the treatmentgroups. The body weight of the animals increased to different degrees inall the groups, compared with the weight at the beginning of theadministration. It was surprisingly found that the percentage bodyweight increase in the groups treated with compound C8 were twice asmuch as that in the group treated with a gemcitabine injection. It isshown that the test compound of the present application has significantpharmacological efficacy, as well as better safety and tolerabilityprofiles, and an organism treated with it would recover more easily.

6.2 Colorectal Cancer Cell HCT-116

6.2.1 Tumor Regression

Compared with the vehicle control group and the positive control(gemcitabine injection) group, in the groups treated with compound C8,the tumor growth was significantly inhibited, and compound C8 was shownto have excellent safety and tolerability profiles.

The results of TGI and tumor regression of each group are shown in Table4.

The results (obtained from observation at 14 days after the lastadministration) indicated that in the groups treated with compound C8(i.v. and p.o.), complete tumor regression occurred in 1 animal, andpartial tumor regression occurred in 7 animals; while no tumorregression occurred in the group treated with a gemcitabine injection.

TABLE 4 the results of TGI and tumor regression in a model of colorectalcancer cell HCT-116. Adminis- Dosage tration TGI Tumor Group Compound(μmol/kg) route (%) regression 1 Vehicle control — i.v. / 0 2Gemcitabine 190 i.v. 92 0 4 Compound C8 190 i.v. 111 1/8 CR, 7/8 PR 5Compound C8 190 p.o. 113 1/8 CR, 7/8 PR

6.2.2 Body Weight Change and Mortality of the Animals

At the end of the observation (which was continued for 14 days after thelast administration), the body weight of the animals decreased (by 2.4%)in the group treated with a gemcitabine injection, while the body weightof the animals increased in all the remaining groups, compared with theweight at the beginning of the administration. No animal deaths occurredin any of the groups. The detailed results are shown in Table 5.

TABLE 5 body weight change and mortality of the animals in each groupAdminis- Body Dosage tration weight Group Compound (μmol/kg) routechange Mortality 1 Vehicle control — i.v. +8.6% 0 2 Gemcitabine 190 i.v.−2.4% 0 4 Compound C8 190 i.v. +7.4% 0 5 Compound C8 190 p.o. +8.9% 0

In the test on mice bearing a tumor of colorectal cancer cell lineHCT-116, compared with the vehicle control group, no tumor regressionoccurred in the group treated with a gemcitabine injection; while in thegroups treated with compound C8 (including intravenous administrationand oral administration), complete tumor regression occurred in 1animal, and partial tumor regression occurred in 7 animals. It was thusdemonstrated that compound C8 had an excellent anti-tumor effect invivo. Meanwhile, compound C8 has good polarity and lipid solubility, aswell as improved metabolic properties and bioavailability.

Experimental Example 3: In Vivo Activity Test

1. Cell Lines for the Test, Tumor Cell Inoculation, and Grouping ofAnimals

According to methods similar to those in sections 1 to 2 in Experimentalexample 2, pancreatic cancer cell BxPC-3 was cultured as a monolayer invitro, and inoculated, and the animals were randomized into groups.

2. Sample Preparation

Sulfobutyl ether-β-cyclodextrin (SE-β-CD) was formulated withphysiological saline to form a 10% solution, which was then filteredthrough a 0.22 μm sterile filter for later use. An appropriate amount ofthe test compound was weighted out, and added in DMSO. The 10% solutionof SE-β-CD was then added according to the desired concentration, andthe final concentration of DMSO was adjusted to 2.5%. A gemcitabineinjection (a positive control) was diluted to the desired concentrationwith physiological saline. A 10% solution of SE-β-CD containing 2.5%DMSO was prepared as a vehicle control.

3. Test Method

Mice bearing a tumor having a volume of 100-200 mm³ were selected, andrandomized into 14 groups (7 mice per group). The dosing volume was 20mL/kg, and the administration (intravenous administration (i.v.)) wasperformed once every 3 days, for 4 times in total. The tumor volume andbody weight were measured twice a week after the administration, and themortality of animals was observed every day.

4. Test Indexes

For statistical calculations of the test indexes, please refer toExperimental example 2.

5. Test Results

TABLE 6 the efficacy on a subcutaneous xenograft of human pancreaticcancer cell BxPC-3 in a nude mouse Administration Compound Dosage(mmol/kg) route TGI (%) Vehicle control / i.v. — Gemcitabine injection0.04 i.v. −2.2 Compound C8 0.04 i.v. 26.9 Gemcitabine injection 0.12i.v. 28.9 Compound C8 0.12 i.v. 74.9 Gemcitabine injection 0.24 i.v.45.5 Compound C8 0.24 i.v. 82.9

As can be seen from the table above, compound C8 of the presentinvention can effectively inhibit the growth of a subcutaneous xenograftof human pancreatic cancer cell BxPC-3 in a nude mouse at variousdosages, and the pharmacological effect of compound C8 is significantlybetter than that of the gemcitabine injection.

Experimental Example 4: In Vivo Activity Test

1. Cell Lines for the Test, Tumor Cell Inoculation, Grouping of Animals,and Sample Preparation

According to methods similar to those in sections 1 to 3 in Experimentalexample 2, pancreatic cancer cell BxPC-3 was cultured as a monolayer invitro, and inoculated; the animals were randomized into groups; andsamples were prepared.

2. Test Method

Mice bearing a tumor having a volume of 80-250 mm³ were selected, andrandomized into 6 groups (8 mice per group). The dosing volume was 10mL/kg. The tumor volume and body weight were measured twice a week afterthe administration, and the mortality of animals was observed every day.

3. Test Indexes

For statistical calculations of the test indexes, please refer toExperimental example 2.

4. Test Results

The test results obtained by administrating twice a week for 3 weeks intotal are shown in table 7-1.

TABLE 7-1 the efficacy on a subcutaneous xenograft of human pancreaticcancer cell BxPC-3 in a nude mouse Administration Compound Dosage(mmol/kg) route TGI (%) Vehicle control / p.o. / Compound C8 0.06 p.o.47.7 Gemcitabine injection 0.12 i.v. 23.6 Compound C8 0.12 p.o. 53.2

The test results obtained by administrating (intravenous administration(i.v.) or oral administration (p.o.)) once a week for 3 weeks are shownin table 7-2.

TABLE 7-2 the efficacy on a subcutaneous xenograft of human pancreaticcancer cell BxPC-3 in a nude mouse Administration Compound Dosage(mmol/kg) route TGI (%) Gemcitabine injection 0.23 i.v. 23.6 Compound C80.23 p.o. 51.0

In this test, compound C8 of the present invention can effectivelyinhibit the growth of a subcutaneous xenograft of human pancreaticcancer cell BxPC-3 in a nude mouse at various dosages, and thepharmacological effect of compound C8 is significantly better than thatof the gemcitabine injection. Moreover, compound C8 exhibits excellentoral bioavailability. As oral administration is an administration routemore acceptable to a patient, compound C8 of the present invention hasimproved tolerability in a patient.

Experimental Example 5: In Vivo Activity Test

1. Cell Lines for the Test, Tumor Cell Inoculation, and Grouping ofAnimals

According to methods similar to those in sections 1 to 2 in Experimentalexample 2, pancreatic cancer cell Capan-1 was cultured as a monolayer invitro, and inoculated, and the animals were randomized into groups.

2. Sample Preparation

Samples were prepared as described in Experimental example 2.

3. Test Method

Mice bearing a tumor having a volume of 100-200 mm³ were selected, andrandomized into 7 groups (7 mice per group). The dosing volume was 20mL/kg, and the administration (intravenous administration (i.v.) or oraladministration (p.o.)) was performed once every 3 days, for 6 times intotal. The tumor volume and body weight were measured twice a week afterthe administration, and the mortality of animals was observed every day.

4. Test Indexes

For statistical calculations of the test indexes, please refer toExperimental example 2.

5. Test Results

TABLE 8 the efficacy on a subcutaneous xenograft of human pancreaticcancer cell Capan-1 in a nude mouse Administration Compound Dosage(mmol/kg) route TGI (%) Vehicle control — p.o. — Gemcitabine injection0.02 i.v. 15.4 Gemcitabine injection 0.19 i.v. 78.9 Compound C8 0.02p.o. 25.6 Compound C8 0.06 p.o. 79.1 Compound C8 0.19 p.o. 138.5Compound C8 0.06 i.v. 81.8

As can be seen from the table above, compound C8 of the presentinvention can effectively inhibit the growth of a subcutaneous xenograftof human pancreatic cancer cell Capan-1 in a nude mouse at variousdosages, and the pharmacological effect of compound C8 is significantlybetter than that of the gemcitabine injection. Moreover, the effectsachieved by oral and intravenous administration of compound C8 werebetter than that achieved by gemcitabine administrated in a dose threetimes higher than that of C8.

Experimental Example 6: In Vivo Activity Test

This test was performed according to experimental example 5.

Mice bearing a tumor having a volume of 100-200 mm³ were selected, andrandomized into 4 groups (6 mice per group). The dosing volume was 10mL/kg, and the administration (intravenous administration (i.v.) or oraladministration (p.o.)) was performed once every 3 days, for 6 times intotal. The tumor volume and body weight were measured twice a week afterthe administration, and the mortality of animals was observed every day.

TABLE 9 the efficacy on a subcutaneous xenograft of human pancreaticcancer cell PANC-1 in a nude mouse Administration Compound Dosage(mmol/kg) route TGI (%) Vehicle control — p.o. — Gemcitabine injection0.06 i.v. 64.4 Compound C8 0.06 p.o. 155 Compound C8 0.19 p.o. 195

As can be seen from the table above, compound C8 of the presentinvention can effectively inhibit the growth of a subcutaneous xenograftof human pancreatic cancer cell Capan-1 in a nude mouse at variousdosages, and the pharmacological effect of compound C8 is significantlybetter than that of the gemcitabine injection.

Experimental Example 7: Toxicology Tests

This experimental example was use to demonstrate the significantlyimproved safety profile of the compound of present invention.

1. Oral Toxicity Test in Mice (Administration for 7 Days)

Normal Male and female Kunming mice (SPF grade, obtained from LaboratoryAnimal Center in Sichuan Academy of Chinese Medicine Science) wererandomized by weight into groups. The test compound and vehicle controlwere formulated according to Experimental example 2. The dosage volumewas 10 mL/kg, and the administration was performed by oral gavage, onceper day for 7 consecutive days.

The mortality and clinical symptoms observed in this test are shown intable 10.

TABLE 10 the results of mortality and clinical symptoms observed in miceadministered repeatedly for 7 days Dosage Dosage Results Group Sample(mg/kg) (μmol/kg) (3 Male + 3 Female) 1 Purified water 0 0 No abnormalsymptoms 2 Vehicle control 0 0 No abnormal symptoms 3 Compound C8 ~6 ~12No abnormal symptoms 4 Compound C8 ~20 ~38 No abnormal symptoms 5Compound C8 ~41 ~77 One animal arched, and then recovered. 6 Compound A~20 ~77 The animals all exhibited severe abnormal symptoms, and two ofthem died.

According to the table above, the toxic reactions resulted from about 77μmol/kg compound A caused the death of some animals, while the deathcaused by a dosage of about 77 μmol/kg of compound A occurred only whencompound C8 was administered at a very high dosage (˜115 μmol/kg).Moreover, the animals survived at a dosage of about 77 μmol/kg ofcompound C8, which indicated that the toxic effects caused by oraladministration of this compound to mice were mild, the mice can recover,and the reduced toxicity caused by oral administration of compound C8 tomice was thus demonstrated.

2. Intravenous Toxicity Test in Mice (Administration for 7 Days)

This test was used to investigate the toxic reactions after intravenousadministration of compound C8 to normal KM mice for 7 consecutive days.

Test Method

KM mice passing the quarantine control were randomized into 4 groups (3mice/gender/group). The test compound and vehicle control wereformulated according to Experimental example 2. The dosage volume was 10mL/kg, and the specific dosages were as shown in table 11. Themortality, appearance, behavior, mental status, secretion and excretaetc. of the animals were observed every day for 7 consecutive days afterthe administration, and the animals were anatomized on day 8.

TABLE 11 dosages Dosage Dosage Group Drug (mg/kg) (μmol/kg) Animalnumber 1 Physiological saline 0 0 3 male + 3 female 2 Vehicle control 00 3 male + 3 female 3 Compound C8 60.9 115.38 3 male + 3 female 4Compound A 20 76.92 3 male + 3 female

Test Results

There was no significant difference of the indexes between thephysiological saline group and the vehicle group.

The animals from the group treated with compound A exhibited symptomssuch as a hunched stance and weight loss, etc. on day 8, while norelevant abnormalities were observed in group 3 (the group treated withcompound C8). The body weight of the animals treated with compound Adecreased gradually, and on day 8, the body weight of the female andmale mice decreased by 20.2% and 18.1%, respectively; while the bodyweight of the animals from the group treated with compound C8 increasedgradually, and on day 8, the body weight of the female and male miceincreased by 13.1% and 26.7%, respectively. Upon anatomy on day 8,compared with the vehicle group, the leukocyte count in the female andmale animals from the group treated with compound C8 decreased by 45%and 49%, respectively, and the platelet count decreased by 43% and 39%,respectively; while the leukocyte count in the female and male animalsfrom the group treated with compound A decreased by 83% and 87%,respectively, and the platelet count decreased by 71% and 77%,respectively.

All the compounds in the examples were tested according to the methodsdescribed above, and it was found that the compounds in the examples ofthe present invention have substantially better safety profiles thanthose of gemcitabine injection and compound A in the toxicologyexperiments.

By testing the compounds in the examples as described above, it wasfound that the compounds prepared in the present invention, whetheradministered intravenously or orally, all achieved excellent anti-tumoreffects, and tumors showed complete regression or partial regression.More surprisingly, the pharmacological effects achieved by administeringthe compounds of the present invention via two different routes were allbetter than that of the gemcitabine injection (tumors showed no or lessregression in the group treated with the gemcitabine injection), and thedefect of poor oral bioavailability of gemcitabine was completelyovercome.

Unexpectedly, the body weight of the animals in the group treated withthe gemcitabine injection decreased during the experiment, indicatingthat the injection caused certain damages to the test animals; while thebody weight of animals in the groups treated with the compounds in theexamples of the present invention increased during the experiment,indicating the compounds of the present invention have bettertolerability and safety profiles in the animals in different groups.

In summary, the 4′-thio-2′-fluoronucleoside compounds of the presentinvention have excellent pharmacological effects. Compared with theparent compound (compound A), the compounds of the present inventionhave increased lipid solubility, improved bioavailability, reducedirritation, improved absorption, and no issues in metabolic rate. Themost critical breakthroughs of the compounds of the compounds of thepresent invention are significantly reduced toxicity, improved safetyprofile, and efficacy achieved through various routes of administration(intravenous or oral administration).

The present invention has been further described through the abovespecific embodiments. However, it should not be construed that the scopeof the present invention is merely limited to the above examples,technical solutions achieved based on the contents of the presentinvention all fall within the scope of the present invention.

What is claimed is:
 1. A method for the prevention or treatment of anabnormal cell proliferative disease in a mammal, wherein the methodcomprises administering to the mammal an effective amount of a compoundselected from the group consisting of:

or a pharmaceutically acceptable salt, ester, hydrate, solvate thereof,or racemate thereof, or a mixture thereof.
 2. The method according toclaim 1, wherein the abnormal cell proliferative disease is cancerand/or tumor and related disorders thereof.
 3. The method according toclaim 1, wherein the effective amount of the compound is in a unit doseranging from 0.1-1000 mg.
 4. The method according to claim 3, whereinthe effective amount of the compound is in a unit dose ranging from1-800 mg.
 5. The method according to claim 4, wherein the effectiveamount of the compound is in a unit dose ranging from 10-600 mg.
 6. Themethod according to claim 5, wherein the effective amount of thecompound is in a unit dose ranging from 50-450 mg.
 7. The methodaccording to claim 6, wherein the effective amount of the compound is ina unit dose ranging from 100-300 mg.
 8. The method according to claim 1,wherein an additional anti-tumour agent is administered.
 9. The methodaccording to claim 1, wherein the effective amount is in a single doseunit or in multiple dose units.
 10. The method according to claim 2,wherein the cancer and/or tumor and related disorders thereof isselected from the group consisting of cancers in esophagus, stomach,intestine, rectum, mouth, pharynx, larynx, lung, colon, breast, uterus,endometrium, ovary, prostate, testis, bladder, kidney, liver, pancreas,bone, connective tissue, skin, eye, brain and central nervous system, aswell as thyroid cancer, leukemia, Hodgkin disease, lymphoma and myeloma.11. The method according to claim 1, wherein the compound isadministered at a dosage range of 0.1-1000 mg/kg body weight per day.12. The method according to claim 11, wherein the compound isadministered at a dosage range of 1-800 mg/kg body weight per day. 13.The method according to claim 12, wherein the compound is administeredat a dosage range of 10-600 mg/kg body weight per day.
 14. The methodaccording to claim 13, wherein the compound is administered at a dosagerange of 100-400 mg/kg body weight per day.
 15. The method according toclaim 14, wherein the compound is administered at a dosage range of120-250 mg/kg body weight per day.